1,3-butylene glycol product and method for producing 1,3-butylene glycol

ABSTRACT

A high-purity 1,3-butylene glycol product is provided, which is colorless and odorless (or almost colorless and odorless), unlikely to cause coloration and odor over time, and, besides, unlikely to cause an acid concentration increase over time also in a state containing water. A 1,3-butylene glycol product in which at least one of a content of methyl vinyl ketone, a content of acetone, a content of butylaldehyde, a content of acetaldol, a content of a compound represented by Formula (1) below, a content of a compound represented by Formula (2) below, a content of a compound represented by Formula (3) below, and a total content of a compound represented by Formula (4) below and a compound represented by Formula (5) below, is less than 8 ppm.

TECHNICAL FIELD

The present disclosure relates to a method for producing 1,3-butyleneglycol, and a 1,3-butylene glycol product. The present applicationclaims priority from the Japanese Patent Application No. 2019-239974.Japanese Patent Application No. 2019-239975, Japanese Patent ApplicationNo. 2019-239976, Japanese Patent Application No. 2019-239977, JapanesePatent Application No. 2019-239978, and Japanese Patent Application No.2019-239979, all filed in Japan on Dec. 28, 2019, the Japanese PatentApplication No. 2020-006660 filed in Japan on Jan. 20, 2020, and theJapanese Patent Application No. 2020-018910 filed in Japan on Feb. 6,2020, the entire contents of which are incorporated herein by reference.

BACKGROUND ART

1,3-Butylene glycol is a colorless, transparent, and odorless liquid andhas properties, such as low volatility, low toxicity, and highhygroscopicity, and has excellent chemical stability, 1,3-butyleneglycol has a wide range of applications, including raw materials forvarious synthetic resins and surfactants, as well as materials forcosmetics, hygroscopic agents, high boiling point solvents, andantifreezes, etc. Particularly in recent years, 1,3-butylene glycol hasbeen attracting attention for having excellent properties as amoisturizer, and demand is growing in the cosmetic industry.

1,3-Butylene glycol produced by a known production method has had aproblem of acid concentration (acidity) increase when the 1,3-butyleneglycol is left for a long period of time in a state containing water.The cause of the acid concentration increase has been uncertain butthought to be related to by-products contained in crude 1,3-butyleneglycol. Cosmetics typically contain water and require a long period oftime from production to actual use by general consumers. In addition,from the viewpoint, such as storage stability of cosmetics, liquidity isstrictly controlled. When 1,3-butylene glycol produced by a known methodis used in cosmetics, an acid concentration increase can disrupt theliquidity balance of the cosmetics, and this can lead to a loss of theintended effect. In addition, the acid concentration increase ofcosmetics can cause rough skin or the like of the users. Furthermore,there was a case where cosmetics containing no water also have absorbedwater during use or storage, and this has also increased the acidconcentration accordingly. Thus, removing by-products from crude1,3-butylene glycol to yield high-purity 1,3-butylene glycol has beenrequired.

Also, 1,3-butylene glycol produced by a known production method havesometimes had an odor due to effects from by-products. In addition,1,3-butylene glycol transparent immediately after production may becolored over time, which is a problem in storing for a long period oftime. For example, during use and/or storage after use of a cosmetic,the cosmetic is exposed to air. In addition, in production of cosmetics,the production is usually performed in air atmosphere, and the productmay be heated for the purposes of, for example, sterilization. When1,3-butylene glycol produced by a known method is used in cosmetics,sometimes coloration occurs due to the presence of air or effects ofheating. To solve such problems, removing by-products from crude1,3-butylene glycol to yield high-purity 1,3-butylene glycol has beenrequired.

For a method to produce high-purity 1,3-butylene glycol, a methodincluding adding sodium hydroxide to crude 1,3-butylene glycol producedby hydrogen reduction of acetaldols and performing distillation has beenproposed. In addition, other methods have been proposed, including amethod in which an alkali metal base is added to crude 1,3-butyleneglycol from which a high boiling point substance has been removed, themixture is heat-treated, then 1,3-butylene glycol is distilled, and thealkali metal compound and a high boiling point substance are separatedas residues, and subsequently a low boiling point substance is distilledoff from the 1,3-butylene glycol distillate (Patent Documents 1 to 6).Various methods for purifying 1,3-butylene glycol have been thusproposed to produce high-purity 1,3-butylene glycol.

CITATION LIST Patent Document

Patent Document 1: JP 07-258129 A

Patent Document 2: WO 00/07969

Patent Document 3: JP 2001-213822 A

Patent Document 4: JP 2001-213824 A

Patent Document 5: JP 2001-213825 A

Patent Document 6: JP 2001-213828 A

SUMMARY OF INVENTION Technical Problem

However, 1,3-butylene glycol products produced from these purificationmethods still contain by-products and have a problem of having an odor,a problem of increasing acid concentration over time when containingwater, and a problem that coloration occurs over time.

1,3-Butylene glycol is produced, for example, by a method of (1)reduction (hydrogenation) of acetaldols, (2) hydrolysis of 1,3-butyleneoxide, (3) selective hydrocracking of erythritol, (4) selectivehydration of butadiene, (5) hydrogen addition to n-butanol-3-one, (6)hydrogen addition to 1-butanol-3-one, (7) hydrogen addition to3-hydroxy-1-butanoic acid, (8) hydrogen addition to β-butyrolactone, or(9) hydrogen addition to diketene.

Of the production methods, the method of (1) reduction (hydrogenation)of acetaldols to yield 1,3 butylene glycol is preferable. Among them,the method of reduction of acetaldols in a liquid phase is preferable interms of yield. The reasons for this are that acetaldols have a highboiling point, that acetaldols are unstable to heat and readily undergoa dehydration reaction at high temperatures to form crotonaldehyde orthe like, and furthermore, that a reaction rate of the dehydrationreaction is greater than that of the reduction reaction (hydrogenationreaction) at high temperatures. That is, when acetaldols are subjectedto vapor-phase reduction, the temperature inside the reaction systemneeds to be increased to high temperature, but subjecting the acetaldolsto high temperature causes a dehydration reaction to producecrotonaldehyde or the like, and the subsequent reduction reactionproduces by-products, such as butanol. Thus, this results in relativelyreduced yield of the target 1,3-butylene glycol. Thus, to produce ahigh-purity 1,3-butylene glycol product, a liquid phase reduction ratherthan a gas phase reduction is preferably performed.

In production of 1,3-butylene glycol, by-products are generally producedin the production process. For example, in production of 1,3-butyleneglycol by hydrogen reduction of an acetaldol, a low boiling pointsubstance (low boiling point compound) having an unsaturated bond, suchas acetaldehyde, butylaldehyde, crotonaldehyde, acetone, and methylvinyl ketone; a condensate of these (e.g., a trimer of acetaldehyde); ahydride of the above condensate; a condensate of 1,3-butylene glycol andthe above low boiling point substance (e.g., an acetal of 1,3-butyleneglycol and acetaldol); or the like is produced as a by-product. Inaddition, an acetal of crotonaldehyde and 1,3-butylene glycol; an acetalof acetaldehyde and 1,3-butylene glycol; an acetal of a hydride of atrimer of acetaldol, acetaldehyde, and acetaldehyde; or the like isproduced as a by-product. Furthermore, in addition to the above, aceticacid may be present as an impurity in an acetaldol used as a rawmaterial or is used to neutralize sodium hydroxide used in producing anacetaldol, and a condensate of the acetic acid and 1,3-butylene glycol(ester of acetic acid and 1,3-butylene glycol) is formed as aby-product. Moreover, these by-products may have properties as asubstance that causes coloration, a substance that causes odor or asubstance that causes acidity.

Whether the acetal is a substance that causes coloration, a substancethat causes odor or a substance that causes acidity is uncertain, andthe acetal is also considered to have all the properties but isconsidered to have strong properties as a substance that causes odor.Specifically, the acetal itself is unlikely to be a substance thatcauses odor but can form a substance that causes odor by a change overtime or heating. Furthermore, the acetal may be hydrolyzed to formacetaldol, which is a substance that causes odor and has an oxidation(coloration) promoting effect. Thus, the acetal can also be said to be asubstance that causes coloration. Here, the substance that causescoloration is defined as including not only a substance actually havinga hue itself but also a substance changing over time into a substancehaving a hue. The substance that causes odor is defined as including notonly a substance actually emitting an odor itself but also a substancechanging over time into a substance emitting an odor. The substance thatcauses acidity is defined as a substance increasing acid concentrationover time when containing water.

Whether the ester is a substance that causes coloration, a substancethat causes odor or a substance that causes acidity is uncertain, andthe ester is also considered to have all the properties but isconsidered to have strong properties as both a substance that causesodor and a substance that causes acidity. This is because when the esteris hydrolyzed by water, acetic acid is produced.

In production of 1,3-butylene glycol, it is considered that by-productsin the production process may include, in addition to the acetal andester, a wide variety of by-products corresponding to a substance thatcauses coloration, a substance that causes odor, or a substance thatcauses acidity. For example, the hydride of a trimer of acetaldehydedescribed above is considered to possibly correspond to any of asubstance that causes coloration, a substance that causes odor or asubstance that causes acidity.

The by-products described above are difficult to completely remove evenusing a purification means, such as distillation known in the art. Thisis considered to be because crude 1,3-butylene glycol is subjected tohigh temperature conditions and alkali treatment in the purificationstage of the crude 1,3-butylene glycol, and new by-products are producedaccordingly. For these reasons, as described above, the 1,3-butyleneglycol products of Patent Documents 1 to 6 contain a wide variety ofby-products, thus have an odor and are colored over time, andfurthermore, increase acid concentration over time in a state containingwater.

Thus, an object of the present disclosure is to provide a high-purity1,3-butylene glycol product that is colorless and odorless (or almostcolorless and odorless), unlikely to cause coloration and odor overtime, and, besides, unlikely to cause an acid concentration increaseover time also in a state containing water.

Furthermore, another object of the present disclosure is to provide amoisturizer and a cosmetic product that have excellent moisturizingperformance and can retain high quality for a long period of time.

Further, another object of the present disclosure is to provide a methodfor industrially efficiently producing high-purity 1,3-butylene glycolhaving properties of being colorless and odorless (or almost colorlessand odorless), unlikely to cause coloration over time, and, besides,unlikely to cause an acid concentration increase over time also in astate containing water.

Solution to Problem

As a result of diligent research to achieve the above purposes, theinventors of the present disclosure have found that specific ninecompounds and, further, acetaldehyde and crotonaldehyde are substancesthat cause coloration, odor, an increase in coloration over time, anincrease in odor over time, and an acid concentration increase. Then,the inventors have found a method for suppressing mixing of thesecompounds into a 1,3-butylene glycol product. More specifically, theinventors have found that, by adjusting contents of specific impuritiesand a concentration of 1,3-butylene glycol in charged liquids into aproduct column and a high boiling point component removal column and,further, by adjusting reaction conditions (particularly, increasing apartial pressure of hydrogen in a reactor) in a reaction step (e.g.,hydrogenation of an acetaldol), it is possible to produce 1,3-butyleneglycol having the properties of being colorless and odorless (or almostcolorless and odorless), unlikely to cause coloration and odor overtime, and, besides, unlikely to cause an acid concentration increaseover time also in a state containing water. The present disclosure hasbeen completed by further studying based on these findings.

That is, the present disclosure provides a 1,3-butylene glycol productin which at least one of eight contents: a content of methyl vinylketone, a content of acetone, a content of butylaldehyde, a content ofacetaldol, a content of a compound represented by Formula (1) below, acontent of a compound represented by Formula (2) below, a content of acompound represented by Formula (3) below, and a total content of acompound represented by Formula (4) below and a compound represented byFormula (5) below, is less than 8 ppm.

In the 1,3-butylene glycol product, a sum of the content of methyl vinylketone, the content of acetone, the content of butylaldehyde, thecontent of acetaldol, the content of the compound represented by Formula(1), the content of the compound represented by Formula (2), the contentof the compound represented by Formula (3), the content of the compoundrepresented by Formula (4), and the compound represented by Formula (5),may be less than 71 ppm.

In the 1,3-butylene glycol product, at least the content of acetaldol ispreferably less than 8 ppm.

In the 1,3-butylene glycol product, at least the content of the compoundrepresented by Formula (3) is preferably less than 8 ppm.

In the 1,3-butylene glycol product, a total content of methyl vinylketone, acetone, and butylaldehyde is preferably 24 ppm or less.

In the 1,3-butylene glycol product, a total content of the compoundrepresented by Formula (1), the compound represented by Formula (2), thecompound represented by Formula (4), and the compound represented byFormula (5) is preferably 24 ppm or less.

In the 1,3-butylene glycol product, a content of acetaldehyde ispreferably less than 4 ppm and a content of crotonaldehyde is preferablyless than 2 ppm.

In the 1,3-butylene glycol product, an acid concentration is preferablyless than 11 ppm in terms of acetic acid, and, after a 90 wt. % aqueoussolution has been kept at 100° C. for 1 week, an acid concentration ispreferably less than 23 ppm in terms of acetic acid.

In the 1,3-butylene glycol product, an APHA is preferably 6 or less,and, after the 1,3-butylene glycol product has been kept at 180° C. for3 hours in air atmosphere, an APHA is 78 or less.

Further, in the 1,3-butylene glycol product, an initial boiling point ispreferably higher than 203° C. and/or a dry point is preferably 209° C.or lower.

In the 1,3-butylene glycol product, a potassium permanganate test valueis preferably 30 minutes or longer.

In addition, the present disclosure provides a moisturizer containingthe 1,3-butylene glycol product.

Furthermore, the present disclosure provides a cosmetic productcontaining the moisturizer.

The present disclosure further provides a method for producing1,3-butylene glycol to yield purified 1,3-butylene glycol from areaction crude liquid containing 1,3-butylene glycol,

the method (hereinafter sometimes referred to as “producing method 1 ofthe present disclosure”) including: performing dehydration includingremoving water by distillation, removing a high boiling point componentincluding removing a high boiling point component by distillation, andperforming product distillation to yield purified 1,3-butylene glycol,

wherein, in a product column for use in the product distillation, a1,3-butylene glycol charged liquid is subjected to distillation under acondition that a reflux ratio is 0.3 or greater, the 1,3-butylene glycolcharged liquid having a content of acetaldehyde of 500 ppm or less, acontent of crotonaldehyde of 200 ppm or less, a content of water of 0.7wt. % or less, and a concentration of 1,3-butylene glycol of 97.6 area%, according to a gas chromatographic analysis performed underconditions set forth below.

The conditions for the gas chromatographic analysis are as follows:

Analytical Column: a column with dimethylpolysiloxane as a stationaryphase, having a length of 30 m, an inner diameter of 0.25 mm, and a filmthickness of 1.0 μm

Heating conditions: heating from 80° C. to 120° C. at CI/min. thenheating again to 160° C. at 2° C./min and maintaining for 2 minutes, andfurther heating to 230° C. at 10° C./min and maintaining at 230° C. for18 minutes

Sample Introduction Temperature: 250° C.

Carrier Gas: helium

Column Gas Flow Rate: 1 mL/min

Detector and Detection Temperature: a flame ionization detector (FID),280° C.

In the method for producing 1,3-butylene glycol, at least a portion of adistillate of the product column may be recycled to a step before theperforming product distillation, the step including dehydration,dealcoholization, low boiling point component removal, or a step beforethese steps.

The present disclosure also provides a method for producing 1,3-butyleneglycol to yield purified 1,3-butylene glycol from a reaction crudeliquid containing 1,3-butylene glycol,

the method (hereinafter sometimes referred to as “producing method 2 ofthe present disclosure”) including: performing dehydration includingremoving water by distillation and removing a high boiling pointcomponent including removing a high boiling point component bydistillation,

wherein, in a high boiling point component removal column for use in theremoving a high boiling point component, a charged liquid containing1,3-butylene glycol is subjected to distillation under a condition thata reflux ratio is 0.03 or greater, the charged liquid having a contentof acetaldehyde of 500 ppm or less, a content of crotonaldehyde of 200ppm or less, a content of water of 3 wt. % or less, and a concentrationof 1,3-butylene glycol of 96.7 area % or greater, according to a gaschromatographic analysis performed under conditions set forth below.

The conditions for the gas chromatographic analysis are as follows:

Analytical Column: a column with dimethylpolysiloxane as a stationaryphase, having a length of 30 m, an inner diameter of 0.25 mm, and a filmthickness of 1.0 μm

Heating conditions: heating from 80° C. to 120° C. at 5° C./min thenheating again to 160° C. at 2° C./min and maintaining for 2 minutes, andfurther heating to 230° C. at 10° C./min and maintaining at 230° C. for18 minutes

Sample Introduction Temperature: 250° C.

Carrier Gas: helium

Column Gas Flow Rate; 1 mL/min

Detector and Detection Temperature: a flame ionization detector (FID),280° C.

In each of the producing methods, the reaction crude liquid containing1,3-butylene glycol may be a reaction crude liquid produced by hydrogenreduction of an acetaldol.

Each of the producing methods may further include at least one stepselected from alkali treatment including treating a process streamcontaining 1,3-butylene glycol with a base, desalting including removinga salt in a process stream containing 1,3-butylene glycol, anddealcoholization including removing a low boiling point substancecontaining an alcohol in a process stream containing 1,3-butyleneglycol.

In the present disclosure, “1,3-butylene glycol product” means acomposition in which 1,3-butylene glycol occupies a majority of thecomponents (e.g., a 1,3-butylene glycol content is 95 wt. % or greater,preferably 98 wt. % or greater).

Advantageous Effects of Invention

According to the present disclosure, a high-purity 1,3-butylene glycolproduct that is colorless and odorless (or almost colorless andodorless), unlikely to cause coloration and odor over time, and,besides, unlikely to cause an acid concentration increase over time alsoin a state containing water is provided.

Furthermore, the present disclosure provides a moisturizer and acosmetic product that have excellent moisturizing performance and canretain high quality for a long period of time.

Further, the method for producing 1,3-butylene glycol of the presentdisclosure can be used to industrially efficiently produce high-purity1,3-butylene glycol having properties of being colorless and odorless(or almost colorless and odorless), unlikely to cause coloration overtime, and, besides, unlikely to cause an acid concentration increaseover time also in a state containing water.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a flowchart illustrating a producing method (purificationmethod) for a 1,3-butylene glycol product of the present disclosure.

FIG. 2 is a chromatogram showing a gas chromatographic analysis for a1,3-butylene glycol product in Example 1.

FIG. 3 is a chromatogram showing a gas chromatographic analysis for a1,3-butylene glycol product in Example 12.

FIG. 4 is a chromatogram showing a gas chromatographic analysis for a1,3-butylene glycol product in Comparative Example 2.

DESCRIPTION OF EMBODIMENTS 1,3-Butylene Glycol Product

In the 1,3-butylene glycol product according to the present disclosure,at least one of a content of methyl vinyl ketone, a content of acetone,a content of butylaldehyde, a content of acetaldol, a content of acompound represented by Formula (1) below, a content of a compoundrepresented by Formula (2) below, and a content of a compoundrepresented by Formula (3) below, and a total content of a compoundrepresented by Formula (4) below and a compound represented by Formula(5) below, is less than 8 ppm.

Each of the contents of methyl vinyl ketone, acetone, butylaldehyde,acetaldol, the compound represented by Formula (1), the compoundrepresented by Formula (2), the compound represented by Formula (3), thecompound represented by Formula (4), and the compound represented byFormula (5) can be quantified by GC-MS analysis performed under thefollowing conditions. In GC-MS analysis, even very small peaks are allsubjected to mass spectrometry, and each component is quantified. Sincethe analysis is performed for a specific mass, a substance different inmass is not detected even when another impurity overlaps the peak.Therefore, the analysis is more sensitive than GC analysis which will bedescribed below. In the present specification, the unit “ppm” of thecontent of each component by GC-MS analysis means “ppm by weight”.

Conditions for GC-MS Analysis

Analytical Column: a column with dimethylpolysiloxane as a stationaryphase, having a length of 30 m, an inner diameter of 0.25 mm, and a filmthickness of 1.0 μm

Heating conditions: heating from 80° C. to 120° C. at 5° C./min, thenheating again to 160° C. at 2° C./min and maintaining for 2 minutes, andfurther heating to 230° C. at 10° C./min and maintaining at 230° C. for18 minutes

Sample Introduction Temperature: 250° C.

Carrier Gas: helium

Column Gas Flow Rate: 1 mL/min

Ion source temperature: EI 230° C., CI 250° C.

Q Pole temperature: 150° C.

Sample: subjected to analysis as it is

Retention times of peaks of methyl vinyl ketone, acetone, butylaldehyde,acetaldol [CH₃CH(OH)CH₂CH(═O)], and the compound represented by Formula(1) below are usually shorter than a retention time of a peak of1,3-butylene glycol. In the above analytical conditions, the retentiontime of a peak of 1,3-butylene glycol is usually from 5.5 minutes to 7minutes. When a relative retention time of the peak of 1,3-butyleneglycol is defined as 1.0 under the above analysis conditions, a relativeretention time of the peak of methyl vinyl ketone is from 0.3 to 0.5, arelative retention time of the peak of acetone is from 0.3 to 0.5, arelative retention time of the peak of butylaldehyde is from 0.3 to 0.5,a relative retention time of the peak of acetaldol is from 0.4 to 0.6,and a relative retention time of the peak of the compound represented byFormula (1) above is from 0.6 to 0.8. The compound represented byFormula (1) is an acetal compound produced by a reaction of acetaldehydewith 1,3-butylene glycol.

Under the above analysis conditions, retention times of peaks of thecompound represented by Formula (2), the compound represented by Formula(3), the compound represented by Formula (4), and the compoundrepresented by Formula (5) are usually longer than the retention time ofthe peak of 1,3-butylene glycol. When the relative retention time of thepeak of 1,3-butylene glycol is defined as 1.0 under the above analysisconditions, a relative retention time of the peak of the compoundrepresented by Formula (2) is from 1.3 to 1.7, a relative retention timeof the peak of the compound represented by Formula (3) is from 1.0 to1.2, a relative retention time of the peak of the compound representedby Formula (4) is from 1.6 to 2.0, and a relative retention time of thepeak of the compound represented by Formula (5) is from 1.3 to 1.7. Thecompound represented by Formula (2) is an acetal compound produced by areaction of crotonaldehyde with 1,3-butylene glycol. The compoundrepresented by Formula (3) is 1,3-butanediol monoacetate produced by areaction of acetic acid with 1,3-butylene glycol. The compoundrepresented by Formula (4) and the compound represented by Formula (5)are acetaldehyde multimeric acetals [the compound represented by Formula(4) has a hydroxy group, and the compound represented by Formula (5)does not have a hydroxy group).

In the 1,3-butylene glycol product according to the present disclosure,at least one of eight contents: the content of methyl vinyl ketone, thecontent of acetone, the content of butylaldehyde, the content ofacetaldol, the content of the compound represented by Formula (1) below,the content of the compound represented by Formula (2) below, thecontent of the compound represented by Formula (3) below, and the totalcontent of the compound represented by Formula (4) below and thecompound represented by Formula (5) below, is less than 8 ppm (forexample, 7 ppm or less, preferably 6 ppm or less, more preferably 5 ppmor less, even more preferably 4 ppm or less, 3 ppm or less, 2 ppm orless, 1 ppm or less, or 0.5 ppm or less). Thus, among the eightcontents, one content may be less than 8 ppm (for example, 7 ppm orless, preferably 6 ppm or less, more preferably 5 ppm or less, even morepreferably 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less,or 0.5 ppm or less): two contents may be less than 8 ppm (for example, 7ppm or less, preferably 6 ppm or less, more preferably 5 ppm or less,even more preferably 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppmor less, or 0.5 ppm or less), three contents may be less than 8 ppm (forexample, 7 ppm or less, preferably 6 ppm or less, more preferably 5 ppmor less, even more preferably 4 ppm or less, 3 ppm or less, 2 ppm orless, 1 ppm or less, or 0.5 ppm or less), four contents may be less than8 ppm (for example, 7 ppm or less, preferably 6 ppm or less, morepreferably 5 ppm or less, even more preferably 4 ppm or less, 3 ppm orless, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less): five contentsmay be less than 8 ppm (for example, 7 ppm or less, preferably 6 ppm orless, more preferably 5 ppm or less, even more preferably 4 ppm or less,3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less), sixcontents may be less than 8 ppm (for example, 7 ppm or less, preferably6 ppm or less, more preferably 5 ppm or less, even more preferably 4 ppmor less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm orless); seven contents may be less than 8 ppm (for example, 7 ppm orless, preferably 6 ppm or less, more preferably 5 ppm or less, even morepreferably 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less,or 0.5 ppm or less); and all of the eight contents may be less than 8ppm (for example, 7 ppm or less, preferably 6 ppm or less, morepreferably 5 ppm or less, even more preferably 4 ppm or less, 3 ppm orless, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).

In the 1,3-butylene glycol product, among the eight contents: thecontent of methyl vinyl ketone, the content of acetone, the content ofbutylaldehyde, the content of acetaldol, the content of the compoundrepresented by Formula (1), the content of the compound represented byFormula (2), the content of the compound represented by Formula (3), andthe total content of the compound represented by Formula (4) and thecompound represented by Formula (5), at least four (four, five, six,seven or eight) contents are preferably less than 8 ppm (for example, 7ppm or less, preferably 6 ppm or less, more preferably 5 ppm or less,even more preferably 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppmor less, or 0.5 ppm or less). Particularly, all of the eight contentsare preferably less than 8 ppm (for example, 7 ppm or less, preferably 6ppm or less, more preferably 5 ppm or less, and even more preferably 4ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm orless).

In the 1,3-butylene glycol product, among the eight contents: thecontent of methyl vinyl ketone, the content of acetone, the content ofbutylaldehyde, the content of acetaldol, the content of the compoundrepresented by Formula (1), the content of the compound represented byFormula (2), the content of the compound represented by Formula (3), andthe total content of the compound represented by Formula (4), and thecompound represented by Formula (4), at least one (for example, one,two, three, four, . . . or all) of sums of two contents (for example, asum of the content of methyl vinyl ketone and the content of acetone, asum of the content of methyl vinyl ketone and the content of butylaldehyde, a sum of the content of methyl vinyl ketone and the content ofacetaldole, a sum of the content of methyl vinyl ketone and the contentof the compound represented by Formula (1), a sum of the content ofmethyl vinyl ketone and the content of the compound represented byFormula (2), a sum of the content of methyl vinyl ketone and the contentof the compound represented by Formula (3), a sum of the content ofmethyl vinyl ketone and the total content of the compound represented byFormula (4) and the compound represented by Formula (5), and a sum ofthe content of acetone and the content of butyl aldehyde) may be lessthan 16 ppm (for example, 15 ppm or less, preferably 14 ppm or less,more preferably 13 ppm or less, even more preferably 12 ppm or less, andparticularly preferably 11 ppm or less, 10 ppm or less, 9 ppm or less, 8ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less,3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less).

Further, in the 1,3-butylene glycol product, among the eight contents:the content of methyl vinyl ketone, the content of acetone, the contentof butylaldehyde, the content of acetaldol, the content of the compoundrepresented by Formula (1), the content of the compound represented byFormula (2), the content of the compound represented by Formula (3), andthe total content of the compound represented by Formula (4), and thecompound represented by Formula (5), at least one (for example, one,two, three, four, . . . or all) of sums of three contents (for example,a sum of the content of methyl vinyl ketone, the content of acetone, andthe content of butylaldehyde; a sum of the content of methyl vinylketone, the content of acetaldol, and the content of the compoundrepresented by the formula (1); and a sum of the content of acetone, thecontent of butylaldehyde, and the content of acetaldol) may be less than24 ppm (for example, 20 ppm or less, preferably 18 ppm or less, morepreferably 16 ppm or less, even more preferably 14 ppm or less, andparticularly preferably 12 ppm or less, 11 ppm or less, 10 ppm or less,9 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm orless, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5ppm or less).

Also, in the 1,3-butylene glycol product, among the content of methylvinyl ketone, the content of acetone, the content of butylaldehyde, thecontent of acetaldol, the content of the compound represented by Formula(1), the content of the compound represented by Formula (2), the contentof the compound represented by Formula (3), and the total content of thecompound represented by Formula (4), and the compound represented byFormula (5), at least one (for example, one, two . . . or all) of sumsof four contents (for example, a sum of the content of methyl vinylketone, the content of acetone, the content of butylaldehyde, and thecontent of acetaldol; and a sum of the content of acetone, the contentof butylaldehyde, the content of acetaldol, and the content of thecompound represented by Formula (1)) may be less than 32 ppm (forexample, 30 ppm or less, preferably 25 ppm or less, more preferably 20ppm or less, even more preferably 18 ppm or less, and particularlypreferably 16 ppm or less, 14 ppm or less, 12 ppm or less, 10 ppm orless, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppmor less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm orless).

Further, in the 1,3-butylene glycol product, a sum of the content ofmethyl vinyl ketone, the content of acetone, the content ofbutylaldehyde, the content of acetaldol, the content of the compoundrepresented by Formula (1), the content of the compound represented byFormula (2), the content of the compound represented by Formula (3), andthe content of the compound represented by Formula (4) and the contentof the compound represented by Formula (5) may be less than 71 ppm (forexample, 60 ppm or less, preferably 50 ppm or less, more preferably 40ppm or less, even more preferably 30 ppm or less, and particularlypreferably 20 ppm or less, 18 ppm or less, 16 ppm or less, 14 ppm orless, 12 ppm or less, 10 ppm or less, 8 ppm or less, 7 ppm or less, 6ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less,1 ppm or less, or 0.5 ppm or less).

In addition, in the 1,3-butylene glycol product, a sum of the content ofmethyl vinyl ketone, the content of acetone, the content ofbutylaldehyde, the content of acetaldol, and the content of the compoundrepresented by Formula (1), which are contents of impurities generallyshorter in GC retention time than 1,3-butylene glycol, is preferablyless than 47 ppm (for example, 40 ppm or less, preferably 30 ppm orless, more preferably 25 ppm or less, even more preferably 20 ppm orless, and particularly preferably 18 ppm or less, 16 ppm or less, 14 ppmor less, 12 ppm or less, 10 ppm or less, 8 ppm or less, 7 ppm or less, 6ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less,1 ppm or less, or 0.5 ppm or less), and a sum of the content of thecompound represented by Formula (2), the content of the compoundrepresented by Formula (3), the content of the compound represented byFormula (4), and the content of the compound represented by Formula (5),which are contents of impurities generally longer in GC retention timethan 1,3-butylene glycol, is preferably less than 24 ppm (for example,20 ppm or less, preferably 18 ppm or less, more preferably 16 ppm orless, even more preferably 14 ppm or less, and particularly preferably13 ppm or less, 12 ppm or less, 11 μm or less, 10 ppm or less, 9 ppm orless, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppmor less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm orless).

It is preferable that, in the 1,3-butylene glycol product according tothe present disclosure, at least the content of acetaldol be less than 8ppm. The acetaldol generates crotonaldehyde by heat. The crotonaldehydecan be a substance that causes coloration, a substance that causes odor,or a substance that causes acidity. The content of acetaldol is morepreferably 7 ppm or less, even more preferably 6 ppm or less, 5 ppm orless, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5ppm or less.

It is preferable that, in the 1,3-butylene glycol product according tothe present disclosure, at least the content of the compound representedby Formula (3) is less than 8 ppm. The compound represented by Formula(3) generates acetic acid by hydrolysis, which causes acetic acid odor.Also, it increases an acid concentration (acid content) of the product.The content of the compound represented by Formula (3) is morepreferably 7 ppm or less, and even more preferably 6 ppm or less, 5 ppmor less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or0.5 ppm or less.

In the 1,3-butylene glycol product according to the present disclosure,the total content of methyl vinyl ketone, acetone, and butylaldehyde ispreferably 24 ppm or less. All of these compounds have a carbonyl groupand can be a substance that causes coloration, a substance that causesodor, or a substance that causes acidity. The total content of methylvinyl ketone, acetone and butylaldehyde is more preferably 20 ppm orless, and even more preferably 18 ppm or less, 16 ppm or less, 14 ppm orless, 12 ppm or less, 11 ppm or less, 10 ppm or less, 9 ppm or less, 8ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less,3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm or less.

In the 1,3-butylene glycol product according to the present disclosure,the total content of the compound represented by Formula (1), thecompound represented by Formula (2), the compound represented by Formula(4), and the compound represented by Formula (5) is preferably 24 ppm orless. All of these compounds are acetal compounds, which generateacetaldehyde by hydrolysis. The acetaldehyde can be a substance thatcauses coloration, a substance that causes odor, or a substance thatcauses acidity.

In the 1,3-butylene glycol product according to the present disclosure,the content of acetaldehyde is preferably less than 4 ppm (inparticular, less than 2 ppm). Furthermore, the content of crotonaldehydeis preferably less than 2 ppm (particularly less than 1.2 ppm). Theacetaldehyde and the crotonaldehyde can be substances that causecoloration, substances that cause odor, or substances that causeacidity. They also reduce the potassium permanganate test value of theproduct. Note that the acetaldehyde content and the crotonaldehydecontent of the 1,3-butylene glycol product can be quantified by GC-MSanalysis (gas mass spectrometry) described above.

Under the GC-MS analysis conditions, when the relative retention time ofthe peak of 1,3-butylene glycol is defined as 1.0, a relative retentiontime of a peak of acetaldehyde is from 0.3 to 0.5, and a relativeretention time of a peak of crotonaldehyde is from 0.3 to 0.5.

The content of acetaldehyde in the 1,3-butylene glycol product is morepreferably 1.8 ppm or less, even more preferably 1.7 ppm or less, 1.5ppm or less, 1.4 ppm or less, 1.3 ppm or less, 1.2 ppm or less, 1.1 ppmor less, 1.0 ppm or less, 0.9 ppm or less, 0.8 ppm or less, 0.7 ppm orless, 0.6 ppm or less, or 0.5 ppm or less, and particularly preferably0.3 ppm or less (for example, 0.2 ppm or less). Furthermore, the contentof crotonaldehyde in the 1,3-butylene glycol product is more preferably1.0 ppm or less, even more preferably 0.9 ppm or less, 0.8 ppm or less,0.7 ppm or less, 0.6 ppm or less, 0.5 ppm or less, 0.4 ppm or less, or0.3 ppm or less, and particularly preferably 0.2 ppm or less (e.g., 0.1ppm or less).

The 1,3-butylene glycol product preferably has an acid concentration ofless than 11 ppm in terms of acetic acid, and an acid concentration ofless than 23 ppm in terms of acetic acid after a 90 wt. % aqueoussolution has been kept at 100° C. for 1 week.

Desirably, the 1,3-butylene glycol product according to the presentdisclosure preferably has an acid concentration of, for example, 10 ppmor less (preferably 9 ppm or less, more preferably 8 ppm or less, evenpreferably 7 ppm or less, particularly preferably 6 ppm or less, andmost preferably 5 ppm or less, 4 ppm or less, or 3 ppm or less) in termsof acetic acid, and an acid concentration of, for example, 20 ppm orless (preferably 19 ppm or less, 18 ppm or less, 17 ppm or less, or 16ppm or less, more preferably 15 ppm or less, even more preferably 14 ppmor less, 13 ppm or less, 12 ppm or less, 11 ppm or less, andparticularly preferably 10 ppm or less, 9 ppm or less, 8 ppm or less, 7ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less,or 2 ppm or less) in terms of acetic acid after a 90 wt. % aqueoussolution has been kept at 100° C. for 1 week. The 90 wt. % aqueoussolution means an aqueous solution prepared by mixing the 1,3-butyleneglycol product and water (e.g., pure water) to adjust the 1,3-butyleneglycol product to 90 wt. %.

For the acid concentration in terms of acetic acid of the 90 wt. %aqueous solution of the 1,3-butylene glycol product according to thepresent disclosure, a ratio of the acid concentration after the solutionhas been kept at 100° C. for 1 week to the acid concentration before thesolution has kept at 100° C. for 1 week, that is [(acid concentrationafter the solution has been kept at 100° C. for 1 week)/(acidconcentration before the solution has been kept at 100° C. for 1week)×100(%)], is preferably 200% or less, more preferably 150% or less,and even more preferably 120% or less.

Desirably, in the 1,3-butylene glycol product according to the presentdisclosure, an APHA (Hazen color number) is, for example, 6 or less(preferably 5 or less, more preferably 4 or less, even more preferably 3or less, and particularly preferably 2 or less). And after the1,3-butylene glycol product has been kept at 180° C. for 3 hours in airatmosphere, an APHA is, for example, 78 or less (preferably 65 or less,more preferably 60 or less, even more preferably 55 or less, 50 or less,45 or less, 40 or less, 35 or less, 30 or less, 25 or less, 20 or less,and particularly preferably 18 or less, 15 or less, 14 or less, 13 orless, 12 or less, 11 or less, 10 or less, 9 or less, 8 or less, or 7 orless). Furthermore, an APHA, after the 1,3-butylene glycol product hasbeen kept at 100° C. for 75 days in air atmosphere, is, for example, 42or less (preferably 35 or less, 30 or less, 25 or less, 20 or less, 18or less, 16 or less, 15 or less, 14 or less, or 13 or less, morepreferably 12 or less, 11 or less, 10 or less, 9 or less, 8 or less, 7or less, or 6 or less, and even more preferably 5 or less, 4 or less, 3or less, or 2 or less).

For the APHA of the 1,3-butylene glycol product according to the presentdisclosure, a ratio of the APHA after the 1,3-butylene glycol producthas been kept at 100° C. for 75 days to the APHA before the 1,3-butyleneglycol product has been kept at 100° C. for 75 days. [(APHA after the1,3-butylene glycol product has been kept at 100° C. for 75 days)/(APHAbefore the 1,3-butylene glycol product has been kept at 100° C. for 75days)], is not particularly limited, but is preferably 10 or less, morepreferably 8 or less, even more preferably 7 or less, and particularlypreferably 6 or less (for example, 5 or less, 4 or less, or 3 or less).In addition, the ratio is 1 or greater, or may be 2 or greater.

Additionally, the 1,3-butylene glycol product according to the presentdisclosure preferably has an initial boiling point of higher than 203°C. The initial boiling point is preferably 204° C. or higher, morepreferably 205° C. or higher, even more preferably 206° C. or higher or207° C. and particularly preferably 208° C. or higher.

Additionally, the 1,3-butylene glycol product according to the presentdisclosure preferably has a dry point of 209° C. or lower.

The 1,3-butylene glycol product according to the present disclosurepreferably has a potassium permanganate test value (PMT) of 30 minutesor longer. The potassium permanganate test value (PMT) is morepreferably longer than 30 minutes (e.g., 32 minutes or longer), evenmore preferably 35 minutes or longer (e.g., 40 minutes or longer), andparticularly preferably 50 minutes or longer (especially, 60 minutes orlonger).

In the 1,3-butylene glycol product according to the present disclosure,an area ratio (GC area ratio) of the peak of 1,3-butylene glycol ispreferably greater than 98.7%, in the gas chromatographic analysis (GCanalysis) performed under conditions set forth below. Furthermore, atotal area ratio of peaks shorter in retention time than the peak of1,3-butylene glycol is preferably less than 0.3%. Furthermore, a totalarea ratio of peaks longer in retention time than the peak of1,3-butylene glycol is preferably less than 1.2%.

The conditions for the gas chromatographic analysis are as follows:

Analytical Column: a column with dimethylpolysiloxane as a stationaryphase, having a length of 30 m, an inner diameter of 0.25 mm, and a filmthickness of 1.0 μm

Heating conditions: heating from 80° C. to 120° C. at 5° C./min, thenheating again to 160° C. at 2° C./min and maintaining for 2 minutes, andfurther heating to 230° C. at 10° C./min and maintaining at 230° C. for18 minutes

Sample Introduction Temperature: 250° C.

Carrier Gas: helium

Column Gas Flow Rate: 1 mL/min

Detector and Detection Temperature: a flame ionization detector (FID),280° C.

In the present disclosure, the “(peak) area ratio” means a ratio of thearea of a specific peak relative to the sum of the areas of all peaksappearing in the chromatogram. In addition, all peaks mean, for example,all of the peaks appearing in the analysis continued until anddiscontinued at a relative retention time of 7.8, provided that therelative retention time of 1,3-butylene glycol is 1.0. When the arearatios of the peaks are within the ranges described above, theoccurrence of odor, the increase in acid concentration over time in astate containing water, and the coloration over time are reduced.

The area ratio of the peak of 1,3-butylene glycol is 98.8% or greater,more preferably 98.9% or greater, even more preferably 99% or greater,99.1% or greater, 99.2% or greater, 99.3% or greater, 99.4% or greater,99.5% or greater, 99.6% or greater, or 99.7% or greater, andparticularly preferably 99.8% or greater.

The total area ratio of the peaks shorter in retention time than thepeak of 1,3-butylene glycol is preferably 0.28% or less, more preferably0.25% or less, even more preferably 0.23% or less, 0.2% or less, 0.17%or less, 0.15% or less, 0.12% or less, 0.1% or less, 0.07% or less,0.04% or less, 0.03% or less, 0.02% or less, 0.01% or less, or 0.007% orless, and particularly preferably 0.005% or less (for example, 0.002% orless).

The total area ratio of the peaks longer in retention time than the peakof 1,3-butylene glycol is preferably 1% or less, more preferably 0.9% orless, more preferably 0.8% or less, 0.7% or less, 0.6% or less, 0.5% orless, 0.4% or less, 0.3% or less, or 0.2% or less, and particularlypreferably 0.1% or less.

In the 1,3-butylene glycol product according to the present disclosure,a content of water is preferably less than 0.4 wt. %. The content ofwater is preferably 0.3 wt. % or less, more preferably 0.2 wt. % orless, even more preferably 0.1 wt. % or less, 0.07 wt. % or less, 0.05wt. % or less, 0.03 wt. % or less, 0.02 wt. % or less, or 0.01 wt. % orless, and particularly preferably 0.005 wt. % or less. Note that thecontent of water can be quantified by a Karl Fischer water contentmeasurement instrument.

A high-purity and high-quality 1,3-butylene glycol product with littledeterioration in quality over time is provided by suppressing thecontents of the specific nine compounds, and, additionally, by settingthe content of acetaldehyde and the content of crotonaldehyde to withinthe above ranges, by setting the initial boiling point and the dry pointto within the above ranges, and further by setting the potassiumpermanganate test value, the area ratio of the peak of 1,3-butyleneglycol, the total area ratio of the peaks shorter in retention time thanthe peak of 1,3-butylene glycol, and the total area ratio of the peakslonger in retention time than the peak of 1,3-butylene glycol to withinthe above ranges.

Moisturizer and Cosmetic Product

A moisturizer of the present disclosure contains the 1,3-butylene glycolproduct described above. Therefore, the moisturizer has excellentmoisturizing performance. The moisturizer of the present disclosure maycontain a component besides the 1,3-butylene glycol product describedabove, such as a moisturizer component besides the 1,3-butylene glycolproduct described above. In the moisturizer of the present disclosure,the content of the 1,3-butylene glycol product described above is, forexample, 10 wt. % or greater, preferably 30 wt. % or greater, morepreferably 50 wt. % or greater, even more preferably 80 wt. % orgreater, and particularly preferably 90 wt. % or greater, and themoisturizer may be composed of only the 1,3-butylene glycol productdescribed above.

A cosmetic of the present disclosure contains the moisturizer describedabove. The blending amount of the 1,3-butylene glycol product in thecosmetic product of the present disclosure is any amount in which themoisturizing performance can be exhibited according to the type and formof cosmetic. The blending amount of the 1,3-butylene glycol product inthe cosmetic product of the present disclosure is, for example, from0.01 to 40 wt. %, preferably from 0.1 to 30 wt. %, more preferably from0.2 to 20 wt. %, even more preferably from 0.5 to 15 wt. %, andparticularly preferably from 1 to 10 wt. %.

The cosmetic product of the present disclosure may contain, in additionto the 1,3-butylene glycol product, for example, another moisturizer; anoil, such as a vegetable oil, a hydrocarbon oil, a greater fatty acid, agreater alcohol, or a silicone; a surfactant, such as an anionicsurfactant, a cationic surfactant, an amphoteric surfactant, or anonionic surfactant; a preservative, a sequestrant, a thickener, apowder, an ultraviolet absorber, an ultraviolet blocker, a fragrance, ora pH adjuster; or a medicinal ingredient or bioactive component, such asa vitamin preparation, a skin activator, a blood circulation promoter, askin-lightening preparation, an antibacterial agent, or ananti-inflammatory agent.

The cosmetic product of the present disclosure can be a skin cosmeticproduct, such as a lotion, an emulsion, a cream, a gel, a pack, or amask; or a hair cosmetic product, such as a shampoo, a rinse, or a hairrestorer. In addition, the cosmetic product may be a sunscreen cosmeticproduct, a make-up cosmetic product or the like. Furthermore, thecosmetic product can be a pharmaceutical product or quasi drugcontaining a medical component.

The cosmetic product of the present disclosure can be produced byutilizing a method known per se.

Method for Producing 1,3-Butylene Glycol

The 1,3-butylene glycol product according to the present disclosure canbe produced by the producing method of the present disclosure. Theproducing method 1 of the present disclosure is a method for producing1,3-butylene glycol to yield purified 1,3-butylene glycol from areaction crude liquid containing 1,3-butylene glycol (1,3 BG)(hereinafter, sometimes referred to as “crude 1,3-butylene glycol”), themethod including: performing dehydration including removing water bydistillation, removing a high boiling point component including removinga high boiling point component by distillation, and performing productdistillation to yield purified 1,3-butylene glycol. Then, in the productcolumn for use in the performing product distillation, a 1,3-butyleneglycol charged liquid is subjected to distillation under a conditionthat a reflux ratio is 0.3 or greater, the 1,3-butylene glycol chargedliquid having a content of acetaldehyde of 500 ppm or less, a content ofcrotonaldehyde of 200 ppm or less, a content of water of 0.7 wt. % orless, and a concentration of 1,3-butylene glycol of 97.6 area %according to the gas chromatographic analysis performed under conditionsset forth below. A liquid with a concentrated low boiling pointcomponent is distilled from above a charging plate, and 1,3-butyleneglycol is extracted from below the charging plate. The thus-produced1,3-butylene glycol is colorless and odorless (or almost colorless andodorless), unlikely to cause or increase coloration and odor over time,and, besides, unlikely to cause an acid concentration increase over timeeven in a state that the 1,3-butylene glycol contains water. Thus, such1,3-butylene glycol can constitute a 1,3-butylene glycol product.

The conditions for the gas chromatographic analysis are as follows:

Analytical Column: a column with dimethylpolysiloxane as a stationaryphase, having a length of 30 m, an inner diameter of 0.25 mm, and a filmthickness of 1.0 μm

Heating conditions: heating from 80° C. to 120° C. at 5° C./min, thenheating again to 160° C. at 2° C./min and maintaining for 2 minutes, andfurther heating to 230° C. at 10° C./min and maintaining at 230° C. for18 minutes

Sample Introduction Temperature: 250° C.

Carrier Gas: helium

Column Gas Flow Rate; 1 mL/min

Detector and Detection Temperature: a flame ionization detector (FID),280° C.

The producing method 2 of the present disclosure is a method forproducing 1,3-butylene glycol to yield purified 1,3-butylene glycol froma reaction crude liquid containing 1,3-butylene glycol, the methodincluding: performing dehydration including removing water bydistillation and removing a high boiling point component includingremoving a high boiling point component by distillation. In a highboiling point component removal column for use in the removing a highboiling point component, a charged liquid containing 1,3-butylene glycolis subjected to distillation under a condition that a reflux ratio is0.03 or greater, the charged liquid having a content of acetaldehyde of500 ppm or less, a content of crotonaldehyde of 200 ppm or less, acontent of water of 3 wt. % or less, and a concentration of 1,3-butyleneglycol of 96.7 area % or greater according to the gas chromatographicanalysis performed under conditions set forth below. The higher-purity1,3-butylene glycol is distilled from above the charging plate, and aliquid in which a high boiling point component is concentrated isextracted from below the charging plate. The thus-produced 1,3-butyleneglycol is colorless and odorless (or almost colorless and odorless),unlikely to cause or increase coloration and odor over time, and,besides, unlikely to cause an acid concentration increase over time evenin a state that the 1,3-butylene glycol contains water. Thus, such1,3-butylene glycol can constitute a 1,3-butylene glycol product.

The “producing method 1 of the present disclosure” and the “producingmethod 2 of the present disclosure” are collectively referred to as“producing method of the present disclosure” in some cases.

Crude 1,3-butylene Glycol

Examples of the crude 1,3-butylene glycol include (1) a reaction crudeliquid produced by reduction (hydrogenation) of an acetaldol, (2) areaction crude liquid produced by hydrolysis of 1,3-butylene oxide, (3)a reaction crude liquid produced by selective hydrocracking oferythritol, (4) a reaction crude liquid produced by selective hydrationto butadiene. (5) a reaction crude liquid produced by hydrogen additionto n-butanal-3-one, (6) a reaction crude liquid produced by hydrogenaddition to 1-butanol-3-one. (7) a reaction crude liquid produced byhydrogen addition to 3-hydroxy-1-butanoic acid, (8) a reaction crudeliquid produced by hydrogen addition to D-butyrolactone, and (9) areaction crude liquid produced by hydrogen addition to diketene. In thepresent disclosure, the crude 1,3-butylene glycol may be one type or amixture of two or more types of the above (1) to (9). The crude1,3-butylene glycol is preferably (1) the reaction crude liquid producedby reduction (in particular, liquid phase reduction) of an acetaldol.

Hereinafter, a case where the reaction crude liquid produced byreduction (hydrogenation) of an acetaldol is used as the crude1,3-butylene glycol will be mainly described. Note that the reduction(hydrogenation) of an acetaldol is sometimes referred to as“hydrogenation”.

The acetaldol used as a raw material in the hydrogenation is notparticularly limited as long as it is a compound that becomes1,3-butylene glycol by hydrogen reduction. Examples of the raw materialacetaldols include acetaldol; its cyclic dimer paraldol; aldoxane as acyclic trimer of acetaldehyde; and mixtures of these.

The method of producing the acetaldol (e.g., acetaldol or paraldol) isnot particularly limited, but the acetaldol may be, for example, thoseproduced by an aldol condensation reaction of acetaldehyde in thepresence of a basic catalyst or those produced by pyrolysis or the likeof aldoxane. Note that the production of the acetaldol is sometimesreferred to as “acetaldol production” or “acetaldehyde polymerization”.

A reaction crude liquid produced by the reaction described above andcontaining an acetaldol may be neutralized with an acid and used in theproduction of 1,3-butylene glycol. Such a reaction crude liquid maycontain, in addition to an acetaldol, acetaldehyde (AD), crotonaldehyde(CR), another aldehyde component: a low boiling point substance; a highboiling point substance, such as an aldehyde dimer or trimer; water; asalt; and the like. In the present specification, a compound with alower boiling point than that of 1,3-butylene glycol may be referred toas a “low boiling point substance” or “low boiling substance”, and acompound with a higher boiling point than that of 1,3-butylene glycolmay be referred to as a “high boiling point substance” or “high boilingsubstance”.

The reaction crude liquid containing an acetaldol may be subjected to apretreatment, such as dealcoholization distillation, dehydrationdistillation, desalting, alkaline treatment and dealkalizationtreatment, or impurity removal, as necessary, and a product produced byremoving by-products, such as unreacted acetaldehyde and crotonaldehyde,may be used. Examples of the pretreatment method include distillation,adsorption, ion exchange, conversion to a high boiling point substanceby heating, and decomposition. For the distillation, a distillationmethod of various types, such as reduced pressure, normal pressure,increased pressure, azeotropic, extraction, or reaction, can be used. Inparticular, it is preferred that the reaction crude liquid containing anacetaldol is subjected to simple evaporation, distillation, or hydrogenaddition to remove aldehydes such as acetaldehyde and crotonaldehyde,followed by the hydrogenation.

The content of the acetaldol in the raw material for hydrogenation isnot particularly limited but is, for example, preferably 30 wt. % orgreater (e.g., from 30 to 99 wt. %), more preferably 40 wt. % or greater(for example, from 40 to 98 wt. %), 50 wt. % or greater (for example,from 50 to 97 wt. %) or 60 wt. % or greater (for example, from 60 to 95wt. %), and even more preferably from 65 to 90 wt. %, particularlypreferably from 70 to 90 wt. %, and most preferably from 75 to 90 wt. %.With the content of the acetaldol within the above ranges, impuritiescontained in the reaction crude liquid containing 1,3-butylene glycol(crude 1,3-butylene glycol) tend to be reduced.

The raw material for hydrogenation may or may not contain water butpreferably contains water from the viewpoint of the purity of1,3-butylene glycol product. The water content in the raw material forhydrogenation is not particularly limited but is, for example,preferably 2 wt. % or greater, more preferably 5 wt. % or greater, evenmore preferably 10 wt. % or greater, and particularly preferably 15 wt.% or greater. The upper limit may be, for example, 90 wt. %, 80 wt %, 70wt. %, 60 wt. %, 50 wt. %, 40 wt. %, 30 wt. % or 20 wt. %. With thewater content within the above ranges, the acetal of 1,3-butylene glycoland acetaldol contained in the resulting crude 1,3-butylene glycol isdecreased, and thus this tends to increase the purity of the1,3-butylene glycol product finally produced. This is because the rawmaterial for hydrogenation contains water to a certain extent, and theacetal is hydrolyzed into 1,3-butylene glycol accordingly as well ascoexisting acetaldol is reduced into 1,3-butylene glycol.

Examples of the hydrogenation catalyst include Raney nickel. Thehydrogenation catalyst can also be used in a suspended state, and canalso be filled in a reaction vessel and used. The amount of thehydrogenation catalyst to be used is not particularly limited but is,for example, preferably from 1 to 30 parts by weight, more preferablyfrom 4 to 25 parts by weight, even more preferably from 8 to 20 parts byweight, and particularly preferably from 12 to 18 parts by weightrelative to 100 parts by weight of the raw material for hydrogenation.The amount of hydrogen to be used in the reduction reaction is notparticularly limited but is, for example, preferably from 0.5 to 40parts by weight, more preferably from 1 to 30 parts by weight, even morepreferably from 4 to 20 parts by weight, and particularly preferablyfrom 8 to 12 parts by weight relative to 100 parts by weight of the rawmaterial for hydrogenation. A pressure (total pressure, gauge pressure)in a reaction system in the reduction reaction is not particularlylimited but is, for example, preferably from 9 to 70 MPa and morepreferably from 10 to 40 MPa. A hydrogen pressure (partial pressure ofhydrogen) in the reaction system is not particularly limited, but is,for example, from 7 to 60 MPa, and preferably from 10 to 30 MPa. Notethat, from the perspective of reducing the amount of the reducingmaterials such as acetaldehyde and crotonaldehyde, it is better toincrease the hydrogen pressure in the reaction system, and the hydrogenpressure is preferably 10 MPa or greater, and may be 100 MPa. A reactiontemperature in the reduction reaction is not particularly limited butis, for example, from 40 to 150° C., preferably from 50 to 140° C., andmore preferably from 60 to 130° C. A reaction time (residence time) inthe reduction reaction is not particularly limited but is, for example,from 10 to 500 minutes, preferably from 20 to 400 minutes, morepreferably from 30 to 300 minutes, even more preferably from 50 to 280minutes, and particularly preferably from 80 to 250 minutes. The presentreaction can be carried out in any of a batch, semi-batch, or continuousmanner.

For example, the thus-produced crude 1,3-butylene glycol contains a lowboiling point substance (low boiling point compound) having anunsaturated bond, such as acetaldehyde (AD), butylaldehyde,crotonaldehyde (CR), acetone, and methyl vinyl ketone; a condensate ofthese; a condensate of 1,3-butylene glycol and the above low boilingpoint substance (e.g., an acetal of 1,3-butylene glycol and acetaldol):an alcohol such as ethanol, isopropyl alcohol, or butanol; water (forexample, solvent), a salt produced by neutralization or the like, acatalyst (when used in suspension) or the like. These impurities areremoved in the purification, and a 1,3-butylene glycol product (purified1,3-butylene glycol) can be produced.

Purification of Crude 1,3-Butylene Glycol

The production method 1 according to the present disclosure includes, atleast, performing dehydration including removing water by distillation,removing a high boiling point component including removing a highboiling point component by distillation (high boiling point componentremoval distillation), and performing product distillation to yieldpurified 1,3-butylene glycol. In the production method 2 of the presentdisclosure, at least dehydration for removing water by distillation andhigh boiling point component removal for removing a high boiling pointcomponent by distillation (high boiling point component removaldistillation).

In the production method of the present disclosure, the order of theperforming dehydration and the removing a high boiling point componentdoes not matter. In the producing method 1 of the present disclosure,both the performing dehydration and the removing a high boiling pointcomponent are provided prior to the product distillation. The productionmethod according to the present disclosure may include, in addition tothese steps, desalting, alkaline reaction (alkaline treatment), anddealkalization. Additionally, prior to the dehydration, catalystseparation, neutralization by alkali, dealcoholization (low boilingpoint component removal), and the like can be provided. These steps maybe performed in the order described above, but the order of the stepsmay be changed as appropriate except that the dealkalization is providedafter the alkaline reaction. For example, the dealcoholization (lowboiling point component removal), the desalting, the alkaline reaction,and the dealkalization can be provided at appropriate locations, but areusually provided after the hydrogenation. Note that, among theabove-described steps, the catalyst separation, the neutralization byalkali, the dealcoholization (low boiling point component removal), thedesalting, the alkaline reaction, and the dealkalization may be providedas necessary, and do not necessarily have to be provided.

FIG. 1 is a flow sheet of an apparatus illustrating an example of anembodiment of a method for producing 1,3-butylene glycol of the presentdisclosure. A is a dehydration column and is related to the dehydration.B is a desalting column and is related to the desalting. C is adistillation column for removing a high boiling point component (highboiling point component removal column) and is related to the highboiling point component removal distillation (high boiling pointcomponent removal). D is an alkaline reactor and is related to thealkaline reaction. E is a dealkalization column and is related to thedealkalization. F is a product distillation column (product column) andis related to the product distillation. A-1, B-1, C-1, E-1, and F-1 arecondensers. A-2, C-2, and F-2 are reboilers. Hereinafter, an example ofan embodiment of the method for producing 1,3-butylene glycol of thepresent disclosure will be described using the present flow sheet.

Crude 1,3-butylene glycol (corresponding to “X-1”) produced by hydrogenreduction of a raw material for hydrogenation is fed to the dehydrationcolumn A. Note that the crude 1,3-butylene glycol (corresponding to“X-1”) may be fed to the dehydration column A after undergoing thedealcoholization (distillation by a dealcoholization column) forremoving an alcohol such as ethanol and a low boiling point substance.

In the production method of the present disclosure, in the dehydrationcolumn A used in the dehydration, for example, a charged liquidcontaining 1,3-butylene glycol and water is subjected to distillation,and a liquid having a concentrated low boiling point componentcontaining water is distilled from above the charging plate (preferably,the top of the column) (corresponding to “X-2” in FIG. 1 ). Further, acrude 1,3-butylene glycol stream containing 1,3-butylene glycol can beproduced from below the charging plate (preferably, the bottom of thecolumn).

The dehydration column A and any other distillation column forseparating 1,3-butylene glycol can be, for example, perforated-platecolumns, bubble columns, and the like, but are more preferably packedcolumns with a low pressure loss, filled with Sulzer Packing, Melapack(trade names of Sumitomo Heavy Industries, Ltd.). This is because1,3-butylene glycol and trace impurities would be thermally decomposedat a high temperature (e.g., 150° C. or higher) and form a low boilingpoint substance, which is a coloring component, and thus thedistillation temperature is to be lowered. In addition, this is alsobecause a long thermal history (residence time) for 1,3-butylene glycolwould also have a similar effect. Thus, the reboiler employed ispreferably one with a short residence time of the process side fluid,for example, a thin-film evaporator, such as a natural downward flowthin-film evaporator or a forced-stirring thin-film evaporator.

A theoretical number of plates of the dehydration column A is, forexample, from 1 to 100 plates, preferably from 2 to 80 plates, from 3 to80 plates, from 4 to 60 plates, from 5 to 40 plates, from 6 to 30 platesor from 7 to 20 plates, and more preferably from 8 to 15 plates. A feedposition for the charged liquid is, for example, from 10 to 90%,preferably from 20 to 80%, and more preferably from 30 to 70%, and evenmore preferably from 40 to 60% of a height of the column downward fromthe top of the column. In the distillation in the dehydration column A,the pressure (absolute pressure) of the top of the column is, forexample, 101 kPa or less, preferably from 0.1 to 90 kPa, more preferablyfrom 0.5 to 70 kPa, and even more preferably from 1 to 50 kPa, from 2 to30 kPa or from 3 to 20 kPa. and particularly preferably from 4 to 10kPa. Note that the distillation in the dehydration column A may beperformed under increased pressure, in which case the pressure (gaugepressure) at the top of the column may be, for example, 0.2 MPaG orless, or 0.1 MPaG or less.

A concentration of 1,3-butylene glycol in the charged liquid into thedehydration column A is, for example, 9 wt. % or greater, preferably 10wt. % or greater, more preferably 15 wt. % or greater, even morepreferably 20 wt. % or greater, 25 wt. % or greater, 30 wt. % orgreater, 35 wt. % or greater, 40 wt. % or greater, 45 wt. % or greater,50 wt. % or greater, 55 wt. % or greater, or 60 wt. % or greater, andparticularly preferably 70% or greater. An upper limit of theconcentration of 1,3-butylene glycol in the charged liquid into thedehydration column A is, for example, 90 wt. %, 85 wt %, or 80 wt. %.However, in consideration of the hydrogen addition reaction and the likein the step prior to the dehydration, the concentration of water in thecharged liquid into the dehydration column A is preferably greater insome cases. Taken together, the concentration of 1,3-butylene glycol inthe charged liquid into the dehydration column A may be, for example, 1wt. % or greater, 5 wt. % or greater, 10 wt. % or greater, 15 wt. % orgreater, 20 wt. % or greater, 25 wt % or greater, 30 wt. % or greater,35 wt. % or greater, 40 wt % or greater, 50 wt. % or greater, 60 wt. %or greater, 70 wt % or greater, 80 wt. % or greater, or 90 wt. % orgreater. Furthermore, the concentration of 1,3-butylene glycol incharged liquid into the dehydration column A may be, for example, 99 wt.% or less, 95 wt. % or greater, 90 wt. % or less, 85 wt. % or less, 80wt. % or less, 75 wt. % or less, 70 wt. % or less, 65 wt. % or less, 60wt. % or less, 55 wt. % or less, 50 wt. % or less, or 45 wt. % or less.The concentration of 1,3-butylene glycol in the charged liquid into thedehydration column A can be, for example, in the range described aboveby adjusting the reaction conditions in the hydrogenation (for example,the concentration of an acetaldol used as a raw material) and thedistillation conditions of the dealcoholization column (low boilingpoint component removal column) provided before the dehydration columnas needed.

The concentration (wt. %) of 1,3-butylene glycol is a value determinedaccording to the following formula by determining an area proportion (GCarea %) of the peak of 1,3-butylene glycol relative to a total peak areain the gas chromatographic analysis under the following conditions. Notethat the concentration (wt. %) of water in the charged liquid into thedehydration column A is a value measured by the method which will bedescribed below (Karl Fischer method).

Concentration (Wt. %) of 1,3-Butylene Glycol in Charged Liquid intoDehydration Column A=[1−(concentration (wt. %) of water in chargedliquid into dehydration column A)/100]×(GC area % of 1,3-butylene glycoldescribed above)

The conditions for the gas chromatographic analysis are as follows:

Analytical Column: a column with dimethylpolysiloxane as a stationaryphase, having a length of 30 m, an inner diameter of 0.25 mm, and a filmthickness of 1.0 μm

Heating conditions: heating from 80° C. to 120° C. at 5° C./min thenheating again to 160° C. at 2° C./min and maintaining for 2 minutes, andfurther heating to 230° C. at 10° C./min and maintaining at 230° C. for18 minutes

Sample Introduction Temperature: 250° C.

Carrier Gas: helium

Column Gas Flow Rate; 1 mL/min

Detector and Detection Temperature: a flame ionization detector (FID),280° C.

In the production method of the present disclosure, a content ofacetaldehyde in the charged liquid into the dehydration column A is, forexample, 1000 ppm or less, preferably 900 ppm or less, more preferably800 ppm or less, 700 ppm or less, 600 ppm or less, or 500 ppm or less,even more preferably 400 ppm or less, 300 ppm or less, 200 ppm or less,155 ppm or less, or 140 ppm or less, and may be 100 ppm or less, 90 ppmor less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less,ppm or less, or 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm orless, 3 ppm or less, 2 ppm or less, or 1 ppm or less.

The content of crotonaldehyde in charged liquid into the dehydrationcolumn A may be, for example, 400 ppm or less, preferably 300 ppm orless, more preferably 200 ppm or less, even more preferably 150 ppm orless, 130 ppm or less, 117 ppm or less, or 100 ppm or less, and may be90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppmor less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less,5 ppm or less, 3 ppm or less, 2 ppm or less, or 1 ppm or less.

The acetaldehyde content and the crotonaldehyde content in the chargedliquid into the dehydration column A can be reduced, for example, byproviding a dealcoholization column (low boiling point component removalcolumn) upstream of the dehydration column A, and adjusting thedistillation conditions of the dealcoholization column (low boilingpoint component removal column). For example, increasing the refluxratio and the number of plates, and the distillation ratio of thedealcoholization column (low boiling point component removal column) canreduce the acetaldehyde content and the crotonaldehyde content of thecharged liquid into the dehydration column A. Furthermore, the contentscan be adjusted according to the conditions for the hydrogen additionreaction in the hydrogenation, and when hydrogen addition is completelyperformed, the concentrations of acetaldehyde and crotonaldehyde can bereduced to below the detection limit, but there are disadvantages of ahigh reaction pressure, an increase in size of the reaction tank and thelike.

Note that the acetaldehyde content and the crotonaldehyde content of thecharged liquid into the dehydration column A can be quantified by GC-MSanalysis (gas mass spectrometry).

In the production method of the present disclosure, the content of waterin the charged liquid into the dehydration column A is, for example, 90wt. % or less, 85 wt. % or less, 80 wt. % or less, 70 wt. % or less, 60wt. % or less, 50 wt. % or less, or 40 wt. % or less, and preferably 35wt. % or less, more preferably 30 wt. % or less, and even morepreferably 25 wt. % or less. A lower limit of the water content of thecharged liquid into the dehydration column A is, for example, 15 wt. %or 10 wt %. Note that, when the hydrogen addition reaction in thehydrogenation is taken into consideration, the greater the waterconcentration and the smaller the viscosity, the greater the solubilityand dispersity of hydrogen in the liquid, which is advantageous for thehydrogen addition reaction. The water content of the charged liquid intothe dehydration column A can be reduced, for example, by providing adealcoholization column (low boiling point component removal column)upstream of the dehydration column A. and adjusting the distillationconditions of the dealcoholization column (low boiling point componentremoval column). For example, increasing the reflux ratio and the numberof plates, and the distillation ratio of the dealcoholization column(low boiling point component removal column) can reduce the watercontent of the charged liquid into the dehydration column A. Note thatthe water content of the charged liquid into the dehydration column Acan be quantified by the Karl Fischer water content measurementinstrument.

In the production method of the present disclosure, the content of thelow boiling point component (excluding water) in the charged liquid intothe dehydration column A is, for example, 20% or less, preferably 10% orless, more preferably 8% or less, even more preferably 5% or less, andparticularly preferably 3% or less or 2% or less, and may be 1% or less,0.5% or less, or 0.1% or less. The content of the low boiling pointcomponent (also referred to as “low boiling point substance” or “lowboiling substance”) excluding water in the charged liquid into thedehydration column A is a total area proportion (area %) of peaks ofshorter in retention time than the peak of 1,3-butylene glycol relativeto the total peak area in the gas chromatographic analysis under theabove conditions. The content of the low boiling point component(excluding water) in the charged liquid into the dehydration column Acan be reduced, for example, by providing a dealcoholization column (lowboiling point component removal column) upstream of the dehydrationcolumn A, and adjusting the distillation conditions of thedealcoholization column (low boiling point component removal column).For example, increasing the reflux ratio and the number of plates, andthe distillation ratio of the dealcoholization column (low boiling pointcomponent removal column) can reduce the content of the low boilingpoint component (excluding water) in the charged liquid into thedehydration column A. Furthermore, the concentration of the low boilingpoint component (excluding water) in the charged liquid into thedehydration column A can be reduced, for example, by reaction conditions(e.g., reaction temperature) in the hydrogenation.

The content of the high boiling point component in the charged liquidinto the dehydration column A is, for example, 20% or less, preferably10% or less, more preferably 7% or less, 4% or less, 3% or less, or 2%or greater, even more preferably 1% or less, 0.5% or less, 0.4% or less,0.3% or less, 0.2% or less, 0.1% or less, or 0.05% or less, andparticularly preferably 0.01% or less. The content of the high boilingpoint component in the charged liquid into the dehydration column A canbe adjusted, for example, by reaction conditions (e.g., reactiontemperature) in the hydrogenation. The content of the high boiling pointcomponent in the charged liquid into the dehydration column A is a totalarea proportion (area %) of peaks longer in retention time than the peakof 1,3 BG to the total peak area in the gas chromatographic analysisunder the above conditions. (area %).

In the production method of the present disclosure, the reflux ratio[dehydration column reflux amount/dehydration column distilled amount(discharge amount to outside of distillation column)] in the dehydrationcolumn A is, for example, greater than 0.3, preferably 0.4 or greater,0.5 or greater, 0.6 or greater, or 0.7 or greater, 0.8 or greater, 0.9or greater, 1 or greater, 1.1 or greater, 1.2 or greater, 1.3 orgreater, 1.4 or greater, 1.5 or greater, 1.6 or greater, 1.7 or greater,1.8 or greater, 1.9 or greater, 2 or greater, 3 or greater, 4 orgreater, 5 or greater, 6 or greater, 7 or greater, 8 or greater, 9 orgreater, 10 or greater, 15 or greater, 20 or greater or 25 or greater,and more preferably 30 or greater (for example, 40 or greater) from theperspective of reducing the content of the low boiling point substance(including water) in the crude 1,3-butylene glycol stream containing1,3-butylene glycol taken out from below the charging plate of thedehydration column A (preferably, the bottom of the column). Inparticular, in the production method 2 of the present disclosure, thereflux ratio in the dehydration column A is preferably 10 or greater,more preferably 20 or greater, even more preferably 30 or greater, andparticularly preferably 50 or greater. An upper limit of the refluxratio is, for example, 100, preferably 50 from the point of energy cost.In a case where the theoretical number of plates of the dehydrationcolumn A is large, sufficient separation can be performed, even when thereflux ratio is 10 or 20 or less.

In the production method of the present disclosure, the distillationratio in the dehydration column A can be appropriately set in accordancewith the concentration of water in the charged liquid into thedehydration column A. Desirably, the distillation ratio is a sufficientdistillation ratio for the total amount of water in the charged liquidto be distilled. For example, in a case where the concentration of waterin the charged liquid into the dehydration column A is X wt. %, thedistillation ratio in the dehydration column A is preferably X wt. % orgreater. Therefore, the distillation ratio in the dehydration column Ais, for example, 95 wt. % or less, 90 wt. % or less, 85 wt. % or less,80 wt. % or less, 75 wt. % or less, 70 wt. % or less, 65 wt. % or less,60 wt. % or less, 55 wt. % or less, 50 wt. % or less, 45 wt. % or less,40 wt. % or less, 35 wt. % or less, 30 wt. % or less, 25 wt. % or less,20 wt. % or less, 15 wt. % or less, 10 wt. % or less, or 5 wt. % orless. The distillation ratio refers to a proportion (wt. %) of an amountof liquid extracted from above the charging plate of the dehydrationcolumn A (e.g., the top of the column) to the outside of thedistillation column with respect to a charged amount into thedehydration column A.

In the production method of the present disclosure, the 1,3 BG recoveryratio in the dehydration column A is, for example, 99.3% or greater.Note that, in the present specification, the 1.3 BG recovery ratio inthe dehydration column A is a value (%) determined by the followingformula.

{1−[concentration (wt. %) of 1,3 BG in distillate×(distilled amount(part)−recycled amount (part))]/(concentration (wt. %) of 1,3 BG incharged liquid×charged amount (part))}×100

Note that the low boiling point substance and the high boiling pointsubstance may be hydrolyzed by water to produce 1,3 BG, while the highboiling point substance may be formed by polymerization of 1,3 BG.Further, trace impurities may be formed or disappear. Thus, the massbalance in the dehydration column may not always be retained. Thisapplies to the dealcoholization column (low boiling point componentremoval column), the high boiling point component removal column, theproduct column, and other distillation columns.

Next, the crude 1,3-butylene glycol stream containing 1,3-butyleneglycol taken out from below the charging plate of the dehydration columnA (preferably, the bottom of the column) is fed to the desalting columnB. In the desalting column B, the crude 1,3-butylene glycol stream afterthe desalting is produced from the top of the column, and a salt, a highboiling point substance, or the like is discharged from the bottom ofthe column. The bottom ratio (%) of the desalting column B [(desaltingcolumn bottom amount (part)/desalting column charge amount (part)×100]is, for example, from 0.1 to 40 wt. %, preferably from 1 to 35 wt. %,more preferably from 2 to 30 wt. %, even more preferably from 3 to 25wt. %, and particularly preferably from to 20 wt. %, and may be from 7to 15 wt. %. At least a portion of the bottom in the desalting columnmay be recycled to the step prior to the desalting.

The crude 1,3-butylene glycol stream after the desalting described aboveis fed to the high boiling point component removal column C. In the highboiling point component removal column C, the high boiling pointcomponent (high boiling point substance) is discharged from below thecharging plate (preferably, from the bottom of the column). On the otherhand, the crude 1,3-butylene glycol stream after high boiling pointsubstance removal (1,3-butylene glycol with improved purity) is producedfrom above the charging plate.

The high boiling point component removal column C can be, for example, aperforated-plate column, a bubble column, or the like, but is morepreferably a packed column with a low pressure loss, filled with SulzerPacking, Melapack (trade names of Sumitomo Heavy Industries, Ltd.). Thisis because 1,3-butylene glycol and trace impurities would be thermallydecomposed at a high temperature (e.g., 150° C. or higher) and form alow boiling point substance, which is a coloring component, and thus thedistillation temperature is to be lowered. In addition, this is alsobecause a long thermal history (residence time) for 1,3-butylene glycolwould also have a similar effect. Thus, the reboiler employed ispreferably one with a short residence time of the process side fluid,for example, a thin-film evaporator, such as a natural downward flowthin-film evaporator or a forced-stirring thin-film evaporator.

A theoretical number of plates of the high boiling point componentremoval column C is, for example, from 1 to 100 plates, preferably from2 to 90 plates, more preferably from 3 to 80 plates, more preferablyfrom 4 to 70 plates, from 5 to 60 plates, from 8 to 50 plates, or from10 to 40 plates, and particularly preferably from 15 to 30 plates. Afeed position for the charged liquid is, for example, from 10 to 90%,preferably from 20 to 80%, and more preferably from 30 to 70 plates, andeven more preferably from 40 to 60% of a height of the column downwardfrom the top of the high boiling point component removal column. In thedistillation in the high boiling point component removal column C, apressure (absolute pressure) at the top of the column is, for example,from 0.01 to 50 kPa, preferably from 0.1 to 30 kPa, more preferably from0.3 to 20 kPa, and even more preferably from 0.5 to 10 kPa.

In the production method 1 of the present disclosure, a concentration of1,3 BG in the charged liquid into the high boiling point componentremoval column C is, for example, 95% or greater, preferably 96% orgreater (for example, 96.7% or greater), more preferably 97% or greater,even more preferably 98% or greater, and particularly preferably 99% orgreater. In the production method 2 of the present disclosure, theconcentration of 1,3 BG in the charged liquid into the high boilingpoint component removal column C is 96.7% or greater, preferably 97% orgreater, more preferably 98% or greater, and even more preferably 99% orgreater. The concentration of 1,3 BG into the charged liquid into thehigh boiling point component removal column C can be improved byadjusting the distillation conditions of the dehydration column A andthe desalting column B. For example, increasing the reflux ratio of thedehydration column A or increasing the bottom ratio of the desaltingcolumn B can increase the concentration of 1,3 BG in the charged liquidinto the high boiling point component removal column C. Note that theconcentration of the 1,3 BG described above is an area proportion (area%) of a 1, 3 BG peak relative to a total peak area in a gaschromatographic analysis (GC analysis) under the following conditions.

The conditions for the gas chromatographic analysis are as follows:

Analytical Column: a column with dimethylpolysiloxane as a stationaryphase, having a length of 30 m, an inner diameter of 0.25 mm, and a filmthickness of 1.0 μm

Heating conditions: heating from 80° C. to 120° C. at 5° C./min, thenheating again to 160° C. at 2° C./min and maintaining for 2 minutes, andfurther heating to 230° C. at 10° C./min and maintaining at 230° C. for18 minutes

Sample Introduction Temperature: 250° C.

Carrier Gas: helium

Column Gas Flow Rate: 1 mL/min

Detector and Detection Temperature: a flame ionization detector (FID),280° C.

A content of the high boiling point component in the charged liquid intothe high boiling point component removal column C is, for example, 4% orless, preferably 3% or less, more preferably 2% or less, even morepreferably 1% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% orless, 0.1% or less, or 0.05% or less, and particularly preferably 0.01%or less. In particular, in the production method 2 of the presentdisclosure, a content of the high boiling point component in the chargedliquid into the high boiling point component removal column C ispreferably 3% or less, more preferably 2% or less, even more preferably1.5% or less, 1% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2%or less, 0.1% or less, or 0.05% or less, and particularly preferably0.01% or less. The content of the high boiling point component in thecharged liquid into the high boiling point component removal column Ccan be reduced by adjusting the distillation conditions of the desaltingcolumn B. For example, increasing the bottom ratio of the desaltingcolumn B can reduce the content of the high boiling point component inthe charged liquid into the high boiling point component removal columnC. Note that the content of the high boiling point component in thecharged liquid into the high boiling point component removal column C isa total area proportion (area %) of peaks longer in retention time thanthe 1,3 BG peaks relative to the total peak area in the gaschromatographic analysis under the above conditions.

In the production method of the present disclosure, the content ofacetaldehyde in charged liquid into the high boiling point componentremoval column C is, for example, 500 ppm or less, preferably 205 ppm orless (e.g., 200 ppm or less), more preferably 100 ppm or less, even morepreferably 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm orless, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm, or less or10 ppm or less, and particularly preferably 5 ppm or less, and may beless than 2 ppm, or less than 1 ppm. The content of crotonaldehyde inthe charged liquid into the high boiling point component removal columnC is, for example, 200 ppm or less, preferably 110 ppm or less, morepreferably 100 ppm or less, even more preferably 80 ppm or less, 70 ppmor less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less,20 ppm or less, 10 ppm or less, 5 ppm or less, or 3 ppm or less, andparticularly preferably 2 ppm or less, and may be less than 1 ppm. Theacetaldehyde content and the crotonaldehyde content in the chargedliquid into the high boiling point component removal column C can bereduced, for example, by providing a dealcoholization column (lowboiling point component removal column) and a dehydration columnupstream of the high boiling point component removal column C, andadjusting the distillation conditions of the dealcoholization column(low boiling point component removal column) and the dehydration column.For example, increasing the reflux ratio and the number of plates, andthe distillation ratio of the dealcoholization column (low boiling pointcomponent removal column) and the dehydration column can reduce theacetaldehyde content and the crotonaldehyde content of the chargedliquid into the high boiling point component removal column C. Note thatthe acetaldehyde content and the crotonaldehyde content of the chargedliquid into the high boiling point component removal column C can bequantified by GC-MS analysis (gas mass spectrometry).

In the production method of the present disclosure, the content of waterin charged liquid into the high boiling point component removal column Cis, for example, 3 wt. % or less, preferably 2 wt. % or less, morepreferably 1.2 wt. % or less, more preferably 1.1 wt. % or less, 1.0 wt.% or less, 0.95 wt. % or less, 0.9 wt. % or less, 0.8 wt. % or less, 0.7wt. % or less, 0.6 wt. % or less, 0.5 wt. % or less, 0.4 wt. % or less,0.3 wt. % or less, or 0.2 wt. % or less, and particularly preferably 0.1wt. % or less. The content of water in the charged liquid into the highboiling point component removal column C can be reduced by adjusting thedistillation conditions of the dehydration column A For example,increasing the reflux ratio and the number of plates, and thedistillation ratio of the dehydration column A can reduce theconcentration of water in the charged liquid into the high boiling pointcomponent removal column C. Note that the water content of the chargedliquid into the high boiling point component removal column CF can bequantified by the Karl Fischer water content measurement instrument. Inthe production method 2 of the present disclosure, the content of waterin the charged liquid into the high boiling point component removalcolumn C is 3 wt. % or less, preferably 2 wt. % or less, 1.2 wt. % orless, 0.4 wt. % or less, 0.3 wt. % or less, or 0.2 wt. % or less, andparticularly preferably 0.1 wt. % or less, 0.05 wt. % or less, or 0.03wt. % or less.

In the production method of the present disclosure, the content of thelow boiling point component (excluding water) in the charged liquid intothe high boiling point component removal column C is, for example, 1.8%or less, preferably 1.6% or less, more preferably 1.4% or less, morepreferably 1.2% or less, 1.1% or less, 1% or less, 0.9% or less, 0.8% orless, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% orless, or 0.2% or less, and particularly preferably 0.1% or less. Thecontent of the low boiling point component (also referred to as “lowboiling point substance” or “low boiling substance”) excluding water inthe charged liquid into the high boiling point component removal columnC is a total area proportion (area %) of peaks of shorter in retentiontime than the peak of 1,3-butylene glycol relative to the total peakarea in the gas chromatographic analysis under the above conditions. Thecontent of the low boiling point component (excluding water) in thecharged liquid into the high boiling point component removal column Ccan be reduced, for example, by providing a dealcoholization column (lowboiling point component removal column) upstream of the high boilingpoint component removal column C, and adjusting the distillationconditions of the dealcoholization column (low boiling point componentremoval column). For example, increasing the reflux ratio and the numberof plates, and the distillation ratio of the dealcoholization column(low boiling point component removal column) can reduce the content ofthe low boiling point component (excluding water) in the charged liquidinto the high boiling point component removal column C.

In the production method of the present disclosure, the reflux ratio[(high boiling point component removal column reflux amount)/(highboiling point component removal column distilled amount (dischargeamount to outside of distillation column))] in the high boiling pointcomponent removal column C is 0.03 or greater, preferably 0.05 orgreater, more preferably 0.1 or greater, even more preferably 0.2 orgreater, 0.3 or greater, 0.4 or greater, 0.5 or greater, 0.6 or greater,0.7 or greater, 0.8 or greater, 0.9 or greater, 1 or greater, 1.2 orgreater, 1.5 or greater, 2 or greater, 3 or greater, 4 or greater, 5 orgreater, or 10 or greater, and particularly preferably 20 or greater,from the perspective of reducing the dry point of the 1,3-butyleneglycol product. In particular, in the production method 2 of the presentdisclosure, the reflux ratio in the high boiling point component removalcolumn C is preferably 0.1 or greater, more preferably 0.2 or greater,0.3 or greater, 0.4 or greater, 0.5 or greater, 0.6 or greater, 0.7 orgreater, 0.8 or greater, 0.9 or greater, 1 or greater, 1.2 or greater,1.5 or greater, 2 or greater, 3 or greater, 4 or greater, 5 or greater,or 10 or greater, and particularly preferably 20 or greater. An upperlimit of the reflux ratio is, for example, 100, preferably 50 from thepoint of energy cost. In a case where the theoretical number of platesof the high boiling point component removal column C is large,sufficient separation can be performed, even when the reflux ratio inthe high boiling point component removal column C is about 1 or less.

In the production method of the present disclosure, the reflux ratio inthe high boiling point component removal column C is within the rangedescribed above, and thus highly pure 1,3 BG having a very low contentof the high boiling point component and a low dry point can be producedwith a high recovery ratio.

In the production method of the present disclosure, the bottom ratio ofthe high boiling point component removal column C is, for example, lessthan 30 wt. %. Note that it is not limited to the value when the bottomof the high boiling point component removal column is distilled in afurther distillation column and a high boiling point substance isremoved therefrom, and 1,3 BG is yielded as the product. When anextracted amount of the material containing a high boiling pointsubstance to the outside of the system is reduced to less than 30 wt. %with respect to the charged amount into the high boiling point componentremoval column C, it is possible to produce 1,3 BG in a high yield. Notethat the bottom ratio refers to a proportion (wt. %) of an amount ofliquid extracted from below the charging plate (for example, bottom ofthe column) of the high boiling point component removal column C withrespect to a charged amount into the high boiling point componentremoval column C (also including an amount of the liquid recycled, whenthe liquid is recycled to the previous steps which will be describedlater). Note that when the liquid is recycled to the previous stepsdescribed below, the recovery ratio of 1,3 BG is improved as thedischarge ratio to the outside is less.

The bottom ratio of the high boiling point component removal column Ccan also be preferably 25 wt. % or less, more preferably 20 wt. % orless, even more preferably 15 wt. % or less, 10 wt. % or less, 7 wt. %or less, 5 wt. % or less, 4 wt. % or less, 3 wt. % or less, or 2 wt. %or less, and can be 1 wt. % or less, from the perspective of improvingthe recovery ratio of 1,3 BG. In addition, the bottom ratio of the highboiling point component removal column is, for example, 0.01 wt. % orgreater, preferably 0.1 wt. % or greater, 0.5 wt. % or greater, or 1 wt.% or greater, more preferably 2 wt. % or greater, 3 wt. % or greater, 4wt. % or greater, 5 wt. % or greater, 6 wt. % or greater, 7 wt. % orgreater, 8 wt. % or greater, 9 wt. % or greater, 10 wt. % or greater, or15 wt. % or greater, and particularly preferably 20 wt. % or greater,from the perspective of reducing the dry point of the 1,3-butyleneglycol product.

At least a portion of the liquid (hereinafter, sometimes referred to as“bottom”) in which the high boiling point component is concentrated, thehigh boiling point component having been extracted from below thecharging plate of the high boiling point component removal column C, maybe recycled to step prior to the removing a high boiling point component(dashed arrow illustrated in the lower part of the high boiling pointcomponent removal column C in FIG. 1 ). The recovery ratio of 1,3 BG canbe improved by recycling at least a portion of the bottom to the stepprior to the removing a high boiling point component. Note that, in thepresent specification, the recovery ratio of 1,3 BG in the high boilingpoint component removal column C is a value (%) determined by thefollowing formula.

{1−[GC area % of 1,3 BG in bottom×(bottom amount (part)−amount (part) ofbottom recycled]/(GC area % of 1,3 BG in charged liquid×charged amount(part)}×100

Note that the low boiling point substance and the high boiling pointsubstance may be hydrolyzed by water to produce 1,3 BG, while the highboiling point substance may be formed by polymerization of 1,3 BG.Further, trace impurities may be formed or disappear. Thus, the massbalance in the high boiling point component removal column may notalways be retained.

The recovery ratio of 1,3 BG in the high boiling point component removalcolumn C is, for example, greater than 80%, preferably 85% or greater,more preferably 90% or greater, even more preferably 95% or greater, andparticularly preferably 99% or greater.

Examples of the step prior to the removing a high boiling pointcomponent include acetaldehyde polymerization (aldol condensation ofacetaldehyde), reaction (hydrogenation), dealcoholization (low boilingpoint component removal), dehydration, and desalting. The bottom ispreferably recycled to the acetaldehyde polymerization (aldolcondensation of acetaldehyde), among these steps, since 1,3 BG isproduced by hydrolysis of the high boiling point substance. In addition,the hydrogen addition reduction may produce 1.3 BG, and the bottom maybe recycled to the hydrogen addition from that viewpoint.

The amount of the bottom recycled to the step prior to the removing ahigh boiling point component can be appropriately selected within arange of the amount of the bottom. The amount of the bottom recycled tothe step prior to the removing a high boiling point component is, forexample, less than 30 wt. %, preferably 25 wt. % or less with respect tothe charged amount into the high boiling point component removal columnC. Note that the amount of the bottom recycled may be 20 wt. % or less,15 wt. % or less, 10 wt. % or less, 7 wt. % or less, 5 wt. % or less, 4wt. % or less, 3 wt. % or less, 2 wt. % or less, or 1 wt. % or less withrespect to the charged amount into the high boiling point componentremoval column C. In addition, from the perspective of improving therecovery ratio of 1,3 BG in the high boiling point component removalcolumn and the yield throughout the 1,3 BG production process, theamount of the bottom recycled to the step prior to the removing a highboiling point component is, for example, 0.01 wt. % or greater,preferably 0.1 wt. % or greater, more preferably 2 wt. % or greater, 3wt. % or greater, 4 wt. % or greater, 5 wt. % or greater, 7 wt. % orgreater, or 10 wt. % or greater, and particularly preferably 20 wt. % orgreater relative to the amount of charge into the high boiling pointcomponent removal column C. Note that, in a case where the amount of thebottom is minimized as much as possible, 1,3 BG can be recovered in ahigh yield, even without recycle to the previous steps.

The crude 1,3-butylene glycol stream taken out from above the chargingplate of the high boiling point component removal column C can be a1,3-butylene glycol product as it is in the production method 2 of thepresent disclosure. Alternatively, the crude 1,3-butylene glycol streamtaken out from above the charging plate of the high boiling pointcomponent removal column C is subjected to alkaline treatment in thealkaline reactor D described below, and evaporated (or distilled) withthe dealkalization column E, and the distillate at the top of thedealkalization column E can be a 1,3-butylene glycol product.

According to the production method 2 of the present disclosure, thecontent of acetaldehyde and the content of crotonaldehyde in the chargedliquid into the high boiling point component removal column are withinthe specific ranges, and the reflux ratio of the high boiling pointcomponent removal column is within the specific range. Therefore, it ispossible to industrially efficiently yield high-purity 1,3-butyleneglycol that is colorless and odorless (or almost colorless andodorless), unlikely to cause or increase coloration and odor over time,and, besides, unlikely to cause an acid concentration increase over timeeven in a state containing water.

In the production method 1 of the present disclosure, the crude1,3-butylene glycol stream taken out from above the charging plate ofthe high boiling point component removal column C is fed, for example,to the alkaline reactor (e.g., a flow-through tubular reactor) D and istreated with a base (treated with alkali). The base treatment candecompose by-products contained in the crude 1,3-butylene glycol. Thebase is added in the alkaline reactor D or its upstream piping or thelike. The base is added in an amount of, for example, from 0.05 to 10wt. %, preferably from 0.1 to 1.0 wt. % relative to the crude1,3-butylene glycol stream subjected to the alkaline treatment. With theadded amount of the base exceeding 10 wt. %, the base would precipitatein the distillation column, piping, or the like, and this may causeblockage. In addition, the decomposition reaction of a high boilingpoint compound would occur, and by-products may be formed on thecontrary. With the added amount of the base of less than 0.05 wt. %, theeffect of decomposing by-products is reduced.

The base added in the alkaline reactor D or its upstream piping is notparticularly limited but is, for example, preferably an alkali metalcompound. Examples of the alkali metal compound include sodiumhydroxide, potassium hydroxide, sodium (bi)carbonate, and potassium(bi)carbonate. A basic ion exchange resin can also be used as the base.The base is preferably sodium hydroxide or potassium hydroxide from theperspective of reducing the by-products contained in the final1,3-butylene glycol product. The base may be added as is in the solidform but is preferably added in an aqueous solution to facilitateoperation and contact with a solution to be treated. One of the basesdescribed above may be used alone, or two or more may be usedsimultaneously.

The reaction temperature in the alkaline reactor D is not particularlylimited but is, for example, preferably from 90 to 140° C. and morepreferably from 110 to 130° C. The reaction at a reaction temperatureless than 90° C. would require long reaction residence time and thusrequire a reactor with a large volume and make the process uneconomical.The reaction at a reaction temperature exceeding 140° C. would increasecoloration in the final 1,3-butylene glycol product. The reactionresidence time is, for example, preferably from 5 to 120 minutes andmore preferably from 10 to 30 minutes. A reaction residence time shorterthan 5 minutes may cause an insufficient reaction and deteriorate thequality of the final 1,3-butylene glycol product. A reaction residencetime exceeding 120 minutes would require a large reactor and increasethe cost of equipment, and thus would be disadvantageous from theeconomic point of view.

After exiting the alkaline reactor D, the reaction crude liquid streamis fed to the dealkalization column (e.g., thin film evaporator) E asnecessary, and the base and the like are removed from the bottom of thecolumn by evaporation. On the other hand, from the top of thedealkalization column E, a crude 1,3-butylene glycol stream after theremoval of a base (which is used as the 1,3-butylene glycol product, inthe production method 2 of the present disclosure) is produced. Theevaporator used for the dealkalization column E is suitably a naturaldownward flow thin-film evaporator or a forced-stirring thin-filmevaporator with a short residence time for the purpose of reducing thethermal history to the process fluid. A demister may be installed in aspace above the charging position of the dealkalization column (e.g.,thin film evaporator) E, and droplets of a base or the like may beremoved. This makes it possible to prevent the base and the like frombeing mixed into the 1,3-butylene glycol product.

Evaporation is performed in the evaporator used for the dealkalizationcolumn E, for example, under a reduced pressure at the top of the columnof 20 kPa or less (absolute pressure), preferably from 0.5 to 10 kPa(absolute pressure). The temperature of the evaporator is, for example,preferably from 90 to 120° C. The crude 1,3-butylene glycol streamcontaining a low boiling point substance distilled from the top of thecolumn is fed to the product distillation column (product column) F.Note that, as described above, in the production method 2 of the presentdisclosure, the distillate (corresponding to E-1) from the top of thedealkalization column E can be a 1,3-butylene glycol product.

Note that the alkaline reactor D and the dealkalization column E may beinstalled between the desalting column B and the high boiling pointcomponent removal column C, between the dehydration column A anddesalting column B (in this case, the desalting column may also serve asa dealkalization column), or before the dehydration column A. Inaddition, without the alkaline reactor D or the dealkalization column Ebeing provided, the alkaline treatment can be performed by charging thebase into a high boiling point component removal column charging line orinto a dehydration column charging line, or adding the base to thereaction solution after the hydrogenation [and then charging the baseinto the dealcoholization column (low boiling point component removalcolumn)].

In the production method 1 of the present disclosure, in the productcolumn F for use in the product distillation, a charged liquid having aconcentration of 1,3-butylene glycol of, for example, 97.6 area % orgreater determined by GC analysis is distilled, a liquid with aconcentrated low boiling point component is distilled from above thecharging plate (corresponding to “X-6” in FIG. 1 ), and 1,3-butyleneglycol is extracted from below the charging plate (corresponding to “Y”in FIG. 1 ). The extracted 1,3-butylene glycol can be a 1,3-butyleneglycol product.

The product column F can be, for example, a perforated-plate column, abubble column, or the like, but is more preferably a packed column witha low pressure loss, filled with Sulzer Packing, Melapack (trade namesof Sumitomo Heavy Industries, Ltd.). This is because 1,3-butylene glycoland trace impurities would be thermally decomposed at a high temperature(e.g., 150° C. or higher) and form a low boiling point substance, whichis a coloring component, and thus the distillation temperature is to belowered. In addition, this is also because a long thermal history(residence time) for 1,3-butylene glycol would also have a similareffect. Thus, the reboiler employed is preferably one with a shortresidence time of the process side fluid, for example, a thin-filmevaporator, such as a natural downward flow thin-film evaporator or aforced-stirring thin-film evaporator.

A theoretical number of plates of the product column F is, for example,from 1 to 100 plates, preferably from 2 to 90 plates, from 3 to 80plates, from 4 to 70 plates, from 5 to 60 plates, from 8 to 50 plates,or from 10 to 40 plates, and more preferably from 15 to 30 plates. Afeed position for the charged liquid is, for example, from 10 to 90%,preferably from 20 to 80%, and more preferably from 30 to 70%, and evenmore preferably from 40 to 60% of a height of the column downward fromthe top of the column. In the distillation in the product distillationcolumn F, a pressure (absolute pressure) at the top of the column is,for example, from 20 kPa or less, preferably from 0.1 to 10 kPa, morepreferably from 0.3 to 8 kPa, and even more preferably from 0.5 to 5 kPa

In FIG. 1 , in charging to the product column F, the column top vaporfrom the dealkalization column E is condensed in the condenser E-1, andthe resulting condensed liquid is fed, but the column top vapor from thedealkalization column E may be directly fed to the product column F.

The concentration of 1,3-butylene glycol in the charged liquid(1,3-butylene glycol charged liquid) into the product column F is 97.6%or greater, preferably 97.8% or greater, more preferably 98% or greater,even more preferably 98.2% or greater (e.g., 98.4% or greater, 98.6% orgreater, or 98.8% or greater), and particularly preferably 99% orgreater (e.g., 99.1% or greater, 99.2% or greater, 99.3% or greater,99.4% or greater, 99.5% or greater, 99.6% or greater, 99.7% or greater,99.8% or greater, or 99.9% or greater).

The concentration of 1,3-butylene glycol in the charged liquid into theproduct column F can be improved, for example, by adjusting thedistillation conditions of the dehydration column A; providing adealcoholization column (low boiling point component removal column)before the dehydration column A, and adjusting the distillationconditions thereof; or adjusting the distillation conditions of the highboiling point component removal column C. For example, it is possible toincrease the purity of 1,3-butylene glycol in charged liquid into theproduct column F by increasing the reflux ratio of the dealcoholizationcolumn (low boiling point component removal column), the dehydrationcolumn A, and/or the high boiling point component removal column C orincreasing the number of plates.

Note that the concentration of 1,3-butylene glycol in the charged liquidinto the product column F is an area proportion (area %) of the peak of1,3-butylene glycol relative to the total peak area in the gaschromatographic analysis of the following conditions.

The conditions for the gas chromatographic analysis are as follows:

Analytical Column: a column with dimethylpolysiloxane as a stationaryphase, having a length of 30 m, an inner diameter of 0.25 mm, and a filmthickness of 1.0 μm

Heating conditions: heating from 80° C. to 120° C. at 5° C./min, thenheating again to 160° C. at 2° C./min and maintaining for 2 minutes, andfurther heating to 230° C. at 10° C./min and maintaining at 230° C. for18 minutes

Sample Introduction Temperature: 250° C.

Carrier Gas: helium

Column Gas Flow Rate; 1 mL/min

Detector and Detection Temperature: a flame ionization detector (FID),280° C.

In the production method 1 of the present disclosure, the content ofacetaldehyde in charged liquid into the product column F is 500 ppm orless, preferably 205 ppm or less (e.g., 200 ppm or less), morepreferably 150 ppm or less, even more preferably 120 ppm or less, 100ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm orless, 50 ppm or less, 40 ppm or less, 30 ppm or less, ppm or less, or 10ppm or less, and particularly preferably 5 ppm or less, and may be lessthan 2 ppm. The content of crotonaldehyde in the charged liquid into theproduct column F is 200 ppm or less, preferably 150 ppm or less, morepreferably 130 ppm or less, even more preferably 110 ppm or less, 100ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm orless, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5ppm or less, or 3 ppm or less, and particularly preferably 2 ppm orless, and may be less than 1 ppm. The acetaldehyde content and thecrotonaldehyde content in the charged liquid into the product column Fcan be reduced, for example, by providing a dealcoholization column (lowboiling point component removal column) and a dehydration columnupstream of the product column F, and adjusting the distillationconditions of the dealcoholization column (low boiling point componentremoval column) and the dehydration column. For example, increasing thereflux ratio and the number of plates, and the distillation ratio of thedealcoholization column (low boiling point component removal column) andthe dehydration column can reduce the acetaldehyde content and thecrotonaldehyde content of the charged liquid into the product column F.In addition, the acetaldehyde content and the crotonaldehyde content inthe charged liquid into the product column F can be reduced byincreasing the reaction temperature, increasing the residence time, orincreasing the added amount of the base, in the alkaline reaction. Notethat the acetaldehyde content and the crotonaldehyde content of thecharged liquid into the product column F can be quantified by GC-MSanalysis (gas mass spectrometry).

In the production method 1 of the present disclosure, a content of waterin charged liquid into the product column F is 0.7 wt. % or less,preferably 0.6 wt. % or less, 0.5 wt. % or less, 0.4 wt. % or less, 0.3wt. % or less, or 0.2 wt. % or less, and particularly preferably 0.1 wt.% or less. The content of water in the charged liquid into the productcolumn F can be reduced by adjusting the distillation conditions of thedehydration column A. For example, increasing the reflux ratio and thenumber of plates, and the distillation ratio of the dehydration column Acan reduce the concentration of water in the charged liquid into theproduct column F. Note that the water content of the charged liquid intothe product column F can be quantified by the Karl Fischer water contentmeasurement instrument.

The content of the low boiling point component (excluding water) in thecharged liquid into the product column F is, for example, 1.8% or less,preferably 1.6% or less, more preferably 1.4% or less, more preferably1.2% or less, 1.1% or less, 1% or less, 0.9% or less, 0.8% or less, 0.7%or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, or 0.2%or less, and particularly preferably 0.1% or less. The content of thelow boiling point component (also referred to as “low boiling pointsubstance”) excluding water in the charged liquid into the productcolumn F is a total area proportion (area %) of peaks of shorter inretention time than the peak of 1,3-butylene glycol relative to thetotal peak area in the gas chromatographic analysis under the aboveconditions. The content of the low boiling point component (excludingwater) in the charged liquid into the product column F can be reduced,for example, by providing a dealcoholization column (low boiling pointcomponent removal column) upstream of the product column F, andadjusting the distillation conditions of the dealcoholization column(low boiling point component removal column). For example, increasingthe reflux ratio and the number of plates, and the distillation ratio ofthe dealcoholization column (low boiling point component removal column)can reduce the content of the low boiling point component (excludingwater) in the charged liquid into the product column F.

The content of the high boiling point component (excluding water) in thecharged liquid into the product column F is, for example, 1.8% or less,preferably 1.6% or less, more preferably 1.4% or less, more preferably1.2% or less, 1.1% or less, 1% or less, 0.9% or less, 0.8% or less, 0.7%or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, or 0.2%or less, and particularly preferably 0.1% or less. The content of thehigh boiling point component (also referred to as “high boiling pointsubstance” or “high boiling substance”) excluding water in the chargedliquid into the product column F is a total area proportion (area %) ofpeaks of longer in retention time than the peak of 1,3-butylene glycolrelative to the total peak area in the gas chromatographic analysisunder the above conditions. The content of the high boiling pointcomponent (excluding water) in the charged liquid into the productcolumn F can be reduced, for example, by adjusting the distillationconditions of the high boiling point component removal column. Forexample, increasing the reflux ratio, the number of plates, or thebottom ratio of the high boiling point component removal column canreduce the content of the high boiling point component (excluding water)in the charged liquid into the product column F.

In the production method 1 of the present disclosure, the reflux ratio[(product column reflux amount)/(product column distilled amount(discharge amount to outside of distillation column))] in the productcolumn F is 0.3 or greater, preferably 0.4 or greater, more preferably0.5 or greater, 1 or greater, 2 or greater, 3 or greater, 4 or greater,5 or greater, 6 or greater, 7 or greater, 8 or greater, 9 or greater, 10or greater, 20 or greater, or 50 or greater, and particularly preferably400 or greater (for example, 50) or greater), from the perspective ofincreasing the initial boiling point of the 1,3-butylene glycol product.An upper limit of the reflux ratio of the product column F is, forexample, 700 or 1000 from the perspective of energy cost.

In the production method 1 of the present disclosure, the distillationratio of the product column F is, for example, less than 30 wt. %, 29wt. % or less, more preferably 28 wt. % or less, even more preferably 27wt. % or less, 26 wt. % or less, 25 wt. % or less, 24 wt. % or less, 23wt. % or less, 22 wt. % or less, 21 wt. % or less, 20 wt. % or less, 19wt. % or less, 18 wt. % or less, 17 wt. % or less, 16 wt. % or less, 15wt. % or less, 12 wt. % or less, 10 wt. % or less, 8 wt. % or less, 5wt. % or less, 3 wt. % or less, 2 wt. % or less, 1 wt. % or less, 0.8wt. % or less, or 0.6 wt. % or less, and particularly preferably 0.4 wt.% or less, from the perspective of improving the recovery ratio of1,3-butylene glycol. Note that the distillation ratio refers to aproportion (wt. %) of an amount of liquid extracted from above thecharging plate of the product column F (for example, the top of thecolumn) to the outside of the distillation column (when recycled to theprevious step which will be described below, including also the amountof liquid recycled) with respect to a charged amount into the productcolumn F.

At least a portion of the liquid (hereinafter, sometimes referred to as“distillate”) in which the low boiling component is concentrated, whichis extracted from above the charging plate of the product column F, maybe recycled to the step prior to the product distillation (dashed arrowillustrated on the right side of the product column F in FIG. 1 ). Therecovery ratio of 1,3-butylene glycol can be improved by recycling atleast a portion of the distillate to the step prior to the productdistillation.

Examples of the step prior to the product distillation includedehydration and dealcoholization (low boiling point component removal).Note that the dealcoholization (low boiling point component removal) ispreferably provided before the dehydration.

The amount of the distillate recycled to the step prior to the productdistillation can be appropriately selected within the range of theamount of distillate. The amount of the distillate recycle to the stepprior to the product distillation is less than 30 wt. %, for example,with respect to the charged amount into the product column F. Also, fromthe perspective of improving the 1,3 BG recovery ratio in the productcolumn and the yield throughout the process, the amount of thedistillate recycled to the step prior to the product distillation is,for example, 0.01 wt. % or greater, preferably 0.05 wt. % or greater,more preferably 0.1 wt. % or greater, 0.5 wt. % or greater, 1 wt. % orgreater, 1.5 wt. % or greater, 2 wt. % or greater, 3 wt. % or greater, 4wt. % or greater, 5 wt. % or greater, 7 wt. % or greater, or 10 wt. % orgreater, and particularly preferably 20 wt. % or greater with respect tothe charged amount into the product column F.

In the production method 1 of the present disclosure, the content ofacetaldehyde and the content of crotonaldehyde in the charged liquidinto product column F are within the specific ranges, and the refluxratio of the product column F is within the specific range. Therefore,it is possible to industrially efficiently produce high-purity1,3-butylene glycol that is colorless and odorless (or almost colorlessand odorless), unlikely to cause or increase coloration and odor overtime, and, besides, unlikely to cause an acid concentration increaseover time even in a state containing water.

The recovery ratio of 1,3 BG in the product column F is, for example,greater than 80%, preferably 85% or greater, more preferably 90% orgreater, even more preferably 95% or greater, and particularlypreferably 99% or greater.

Note that, in the present specification, the recovery ratio of 1,3 BG inthe product column F is a value (%) determined by the following formula.

{1−[GC area % of 1,3 BG in distillate×(distilled amount (part)−amount(part) of distillate recycled]/(GC area % of 1,3 BG in charged liquidcharged amount (part))×100

Note that, as described above, the low boiling point substance and thehigh boiling point substance may be hydrolyzed by water to produce 1,3BG, while the high boiling point substance may be formed bypolymerization of 1,3 BG. Thus, the mass balance in the product columnmay not always be retained.

Each aspect disclosed in the present specification can be combined withany other feature disclosed herein. Note that each of theconfigurations, combinations thereof, and the like in each of theembodiments are an example, and various additions, omissions, and otherchanges may be made as appropriate without departing from the spirit ofthe present disclosure. The present disclosure is not limited by theembodiments and is limited only by the claims.

EXAMPLES

Hereinafter, the present disclosure will be described more specificallywith reference to examples, but the present disclosure is not limited bythese examples. “Parts” used in the examples means “parts by weight”unless otherwise specified. Gas chromatographic analysis (GC analysis),initial boiling point measurement, and water content measurement wereperformed according to methods which will be described below.

Example 1

The method of producing 1,3-butylene glycol will be described using FIG.1 .

Relative to 100 parts of an acetaldol solution containing 30 wt. % ofwater (mixed solution of 69 parts of acetaldol and 29 parts of water,containing a total of 2 parts of low boiling and high boilingimpurities, Na salt; less than 0.1 parts) as a raw material, 10 parts ofhydrogen were charged in a reactor for liquid-phase hydrogen reduction,and 15 parts of Raney nickel were added as a catalyst. The reactor waskept at 120° C. and 10 MPa (gauge pressure), and liquid-phase hydrogenreduction was performed. After the catalyst was separated, the liquidafter the reaction was neutralized with sodium hydroxide, and crude1,3-butylene glycol (1) containing water was produced.

Note that the acetaldol solution containing 30 wt. % of water used asthe raw material was produced by stirring acetaldehyde and water in thepresence of 100 ppm by weight NaOH at 30° C. at a residence time of 10hours and dimerizing the acetaldehyde [acetaldehyde polymerization(aldol condensation of acetaldehyde)].

The crude 1,3-butylene glycol (1) (corresponding to “X-1” in FIG. 1 )was charged in the dehydration column A. The concentration of1,3-butylene glycol in the charged liquid into the dehydration column Awas 56 wt. %, the water concentration was 40 wt. %, the content ofacetaldehyde (AD) was 130 ppm, the content of crotonaldehyde (CR) was 89ppm, the total area ratio of impurity peaks shorter in retention time(RT) than 1,3-butylene glycol in GC analysis which will be describedlater was 3%, and the total area ratio of impurity peaks longer inretention time than 1,3-butylene glycol was 1%. In the dehydrationcolumn A, the charged liquid containing 1,3-butylene glycol wasdistilled under conditions of a pressure at the top of 10 kPa (absolutepressure) and a reflux ratio of 1, water was extracted from the top ofthe column, and 43 parts (distilled amount) relative to 100 parts of thecharged liquid amount was discharged and removed to the outside of thesystem (corresponding to “X-2” in FIG. 1 ). From the bottom of thecolumn, crude 1,3-butylene glycol (2) having a 1,3-butylene glycolconcentration of 96.9 GC area %, a water content of 0.9 wt. %, a totalarea ratio of impurity peaks shorter in retention time than 1,3-butyleneglycol in the GC analysis which will be described later of 0.8%, a totalarea ratio of peaks longer in retention time than peak of 1,3-butyleneglycols of 2.3%, an acetaldehyde content of 18 ppm, and a crotonaldehydecontent of 17 ppm was produced.

The crude 1,3-butylene glycol (2) was then charged in the desaltingcolumn B. In the desalting column B, a salt, a high boiling pointsubstance, and a portion of 1,3-butylene glycol were discharged as theevaporation residue from the bottom of the column (corresponding to“X-3” in FIG. 1 ). The discharge amount of the evaporation residue was 5parts relative to 100 parts of the charged liquid amount. On the otherhand, from the top of the column, crude 1,3-butylene glycol (3)containing 1,3-butylene glycol, a low boiling point substance, and aportion of a high boiling point substance was produced.

The crude 1,3-butylene glycol (3) was then charged in the high boilingpoint component removal column C. In the high boiling point componentremoval column C, distillation was performed under the conditions of apressure at the top of the column of 5 kPa (absolute pressure) and areflux ratio of 0.05, and a high boiling point substance and a portionof 1,3-butylene glycol were discharged from the bottom of the column(corresponding to “X-4” in FIG. 1 ). The discharge amount from thebottom of the column was 20 parts relative to 100 parts of the chargedliquid amount. On the other hand, 80 parts of crude 1,3-butylene glycol(4) containing a low boiling point substance was produced, as adistillate, from the top of the column.

The crude 1,3-butylene glycol (4) was then charged in the alkalinereactor D. At this time, a 20 wt. % sodium hydroxide aqueous solutionwas added to give a concentration of sodium hydroxide of 0.1 wt. %relative to the charged liquid. The reaction temperature was maintainedat 120° C. in the alkaline reactor D, and a reaction was performed at aresidence time of 20 minutes.

A reaction crude liquid exiting the alkaline reactor D was then chargedin the dealkalization column E. In the dealkalization column E, sodiumhydroxide, a high boiling point substance, and a portion of 1,3-butyleneglycol were discharged from the bottom of the column (corresponding to“X-5” in FIG. 1 ). The discharge amount from the bottom of the columnwas 10 parts relative to 100 parts of the charged liquid amount. On theother hand, from the top of the column 90 parts of crude 1,3-butyleneglycol (5) containing 1,3-butylene glycol and a low boiling pointsubstance were produced. The crude 1,3-butylene glycol (5) containing1,3-butylene glycol and a low boiling point substance was measured forwater content, and subjected to GC analysis and GC-MS analysis. As aresult, the water concentration was 1 wt. %, the area ratio of1,3-butylene glycol was 99%, the total area ratio of impurity peaksshorter in retention time than 1,3-butylene glycol was 0.4%, the totalarea ratio of impurity peaks longer in retention time than 1,3-butyleneglycol was 0.6%, the content of acetaldehyde was 20 ppm, and the contentof crotonaldehyde was 9 ppm.

The crude 1,3-butylene glycol (5) was then charged in the product columnF. In the product column F, 10 parts of the low boiling point substanceand a portion of 1,3-butylene glycol relative to 100 parts of thecharged liquid amount were distilled off from the top of the column(corresponding to “X-6” in FIG. 1 ), and the entire amount wasdischarged to the outside of the system. The operation was performed ata reflux ratio (reflux amount/distilled amount) of 0.5 at that time, and90 parts of a 1,3-butylene glycol product was produced from the bottomof the column (distilled amount: 10 parts) (corresponding to “Y” in FIG.1 ).

The produced 1,3-butylene glycol product was measured for initialboiling point and water content, and subjected to GC analysis and GC-MSanalysis. As a result, the 1,3-butylene glycol product had an initialboiling point of 203.3° C. a dry point of 209° C. a water concentrationof 0.2 wt. %, an area ratio of 1,3-butylene glycol of 99.2%, a totalarea ratio of impurity peaks shorter in retention time than 1,3-butyleneglycol of 0.08%, a total area ratio of impurity peaks longer inretention time than 1,3-butylene glycol of 0.7%, an acetaldehyde contentof 1.5 ppm, and a crotonaldehyde content of 0.9 ppm. The potassiumpermanganate test value was 35 minutes. The 1,3-butylene glycol recoveryratio in the product column F was 90%.

Example 2

The same operation as in Example 1 was performed except that the refluxratio of the dehydration column A was changed to 50. A 1,3-butyleneglycol product was produced from the bottom of the product column F.Note that, due to the changes in conditions employed in the dehydrationcolumn A, the dehydration column bottom composition changed, and thecharged liquid compositions in the high boiling point component removalcolumn C and the product column F changed. As a result, the productqualities changed.

The produced 1,3-butylene glycol product was measured for initialboiling point and water content, and subjected to GC analysis and GC-MSanalysis. As a result, the 1,3-butylene glycol product had an initialboiling point of 206.7° C., a dry point of 208.9° C., a waterconcentration of 0.1 wt. %, an area ratio of 1,3-butylene glycol of99.3%, a total area ratio of impurity peaks shorter in retention timethan 1,3-butylene glycol of 0.05%, a total area ratio of impurity peakslonger in retention time than 1,3-butylene glycol of 0.7%, anacetaldehyde content of 0.7 ppm, and a crotonaldehyde content of 0.7ppm. The potassium permanganate test value was 45 minutes. The1,3-butylene glycol recovery ratio in the product column F was 90%.

Examples 3 to 27

Under the conditions shown in Table 1 and Table 2, the dehydrationcolumn A, the high boiling point component removal column C, and theproduct column F were operated. In Examples 4 to 22 and 24 to 27, theentire amount of the distillate from the product column F was recycledinto hydrogen reduction reactor. In Example 23, the product column F wasnot used, and a distillate at the top of the dealkalization column E(demister was installed in a space above the charging position) was a1,3-butylene glycol product. At this time, the concentration of thesodium hydroxide aqueous solution in the alkaline reactor D was set to1.5 times, and the added amount of the sodium hydroxide aqueous solutionwas set to the half of the amount in Example 1. Thus, the increase inwater content due to alkaline treatment was avoided as much as possible.Note that, when the alkali concentration of the sodium hydroxide aqueoussolution is too high and crystals precipitate. Therefore, heating ispreferably performed to 40° C. or higher. In Table 2, the column “Bottomfrom product column F” of Example 23 shows the composition and physicalproperties of the distillate at the top of the dealkalization column E.Note that, in Example 16, 8 parts of 10 parts of the bottom from thehigh boiling point component removal column was recycled into thehydrogenation, and 2 parts thereof was discharged to the outside of thesystem. In addition, in Example 25, the pressure of the hydrogenaddition reaction was reduced to 7 MPaG (gauge pressure). Therefore, theacetaldehyde content and crotonaldehyde content of the charged liquidinto the dehydration column are high. In Example 26, the reflux ratio ofthe dehydration column was reduced to 0.3, and the purity of1,3-butylene glycol in the charged liquid into the product column wasreduced, and the reflux ratio of the product column was increased to 20.In Example 27, the pressure of the hydrogen addition reaction wasincreased to 40 MPaG (gauge pressure) (the remaining conditions are thesame as in Example 18).

Comparative Example 1

Eighty (80) parts of a 1,3-butylene glycol product was produced from thebottom of the product column F by the same method as in Example 1 exceptthat the reflux ratio of the dehydration column A was changed to 0.5,that the distilled amount was changed to 42 parts, that the reflux ratioof the high boiling point component removal column C was changed to0.02, that the reflux ratio of the product column F was changed to 0.05,and that the distilled amount was changed to 20 parts. The produced1,3-butylene glycol product had an initial boiling point of 193.2° C., adry point of 210.3° C., a water concentration of 0.6 wt. %, an arearatio of 1,3-butylene glycol of 98.3%, a total area ratio of impuritypeaks shorter in retention time than 1,3-butylene glycol of 0.2%, atotal area ratio of impurity peaks longer in retention time than1,3-butylene glycol of 1.5%, an acetaldehyde content of 5 ppm, and acrotonaldehyde content of 4 ppm. The potassium permanganate test valuewas 0 minutes. The 1,3-butylene glycol recovery ratio in the productcolumn F was 80%.

Comparative Example 2

Eighty (80) parts of a 1,3-butylene glycol product was produced from thebottom of the product column F by the same method as in Example 1 exceptthat the charged composition in the dehydration column A was changed,the reflux ratio and the distilled amount were changed to 0.5 and 32parts, respectively, that the reflux ratio of the high boiling pointcomponent removal column C was changed to 0.02, that the reflux ratio ofthe product column F was changed to 0.05, and that the distilled amountwas changed to 20 parts. The produced 1,3-butylene glycol product had aninitial boiling point of 199.0° C., a dry point of 210.1° C., a waterconcentration of 0.4 wt. %, an area ratio of 1,3-butylene glycol of98.5%, a total area ratio of impurity peaks shorter in retention timethan 1,3-butylene glycol of 0.1%, a total area ratio of impurity peakslonger in retention time than 1,3-butylene glycol of 1.4%, anacetaldehyde content of 4 ppm, and a crotonaldehyde content of 2 ppm.The potassium permanganate test value was 5 minutes. The 1,3-butyleneglycol recovery ratio in the product column F was 80%.

Comparative Example 3

Seventy (70) parts of a 1,3-butylene glycol product was produced fromthe bottom of the product column F by the same method as in Example 1except that the charged composition in the dehydration column A waschanged, the reflux ratio and the distilled amount were changed to 0.5and 32 parts, respectively, that the reflux ratio of the high boilingpoint component removal column C was changed to 0.02, that the refluxratio of the product column F was changed to 0.05, and that thedistilled amount was changed to 30 parts. The produced 1,3-butyleneglycol product had an initial boiling point of 203.0° C., a dry point of210.2° C., a water concentration of 0.2 wt. %, an area ratio of1,3-butylene glycol of 98.4%, a total area ratio of impurity peaksshorter in retention time than 1,3-butylene glycol of 0.1%, a total arearatio of impurity peaks longer in retention time than 1,3-butyleneglycol of 1.5%, an acetaldehyde content of 2 ppm, and a crotonaldehydecontent of 1.3 ppm. The potassium permanganate test value was 30minutes. The 1,3-butylene glycol recovery ratio in the product column Fwas 70%.

Comparative Example 4

Eighty (80) parts of a 1,3-butylene glycol product was produced from thebottom of the product column F by the same method as in Example 1 exceptthat the charged composition in the dehydration column A was changed,the distilled amount was changed to 23 parts, that the reflux ratio ofthe high boiling point component removal column C was changed to 0.02,that the reflux ratio of the product column F was changed to 0.1, andthat the distilled amount was changed to 20 parts. The produced1,3-butylene glycol product had an initial boiling point of 203.1° C., adry point of 209.5° C., a water concentration of 0.2 wt. %, an arearatio of 1,3-butylene glycol of 98.8%, a total area ratio of impuritypeaks shorter in retention time than 1,3-butylene glycol of 0.1%, atotal area ratio of impurity peaks longer in retention time than1,3-butylene glycol of 1.1%, an acetaldehyde content of 2 ppm, and acrotonaldehyde content of 1.3 ppm. The potassium permanganate test valuewas 30 minutes. The 1,3-butylene glycol recovery ratio in the productcolumn F was 80%.

Gas Chromatographic Analysis

A gas chromatographic analysis of the target 1,3-butylene glycol productwas performed under the conditions below. A chromatogram of the gaschromatographic analysis of the 1,3-butylene glycol product in Example12 is shown in FIG. 2 . In addition, a chromatogram of the gaschromatographic analysis of the 1,3-butylene glycol product inComparative Example 2 is shown in FIG. 3 .

The conditions for the gas chromatographic analysis are as follows:

Analytical Instrument: Shimadzu GC 2010

Analytical Column: column with dimethylpolysiloxane as a stationaryphase (a length of 30 m, an inner diameter of 0.25 mm, and a filmthickness of 1.0 μm) (Agilent J&W GC column—DB-1, available from AgilentTechnologies Japan, Ltd.)

Heating conditions: heating from 80° C. to 120° C. at 5° C./min. thenheating again to 160° C. at 2° C./min and maintaining for 2 minutes, andfurther heating to 230° C. at 10° C./min and maintaining at 230° C. for18 minutes

Sample Introduction and Temperature: split sample introduction, 250° C.

Gas Flow Rate of Split and Carrier Gas: 23 mL/min, helium

Column Gas Flow Rate and Carrier Gas: 1 mL/nin, helium

Detector and Temperature: a flame ionization detector (FID), 280° C.

Injection Sample: 0.2 μL of a 80 wt. % 1,3-butylene glycol productaqueous solution

Measurement of Initial Boiling Point and Dry Point

Measurement was made according to the test method specified in thenormal pressure distillation test method of JIS K2254 “Petroleumproducts—distillation test method”.

Measurement of Water Content

Measurement was made using a Karl Fischer water content measurementinstrument.

GC-MS Analysis Analytical Instrument: Agilent 6890A-GC/5973A-MSD

Analytical Column: a column with dimethylpolysiloxane as a stationaryphase, having a length of 30 m, an inner diameter of 0.25 mm, and a filmthickness of 1.0 μm

Heating conditions: heating from 80° C. to 120° C. at 5° C./min, thenheating again to 160° C. at 2° C./min and maintaining for 2 minutes, andfurther heating to 230° C. at 10° C./min and maintaining at 230° C. for18 minutes

Sample Introduction Temperature: 250° C.

Carrier Gas: helium

Column Gas Flow Rate; 1 mL/min

Ion source temperature: EI 230° C., CI 250° C.

Q Pole temperature: 150° C.

Sample: subjected to analysis as it was

Potassium Permanganate Test

In the present specification, the potassium permanganate test value(PMT) is a value measured in accordance with the visual colorimetricprocedure of JIS K1351 (1993).

Color Aging Test 1

The target 1,3-butylene glycol product was placed in a wide-mouthbottle, the bottle was stoppered tightly and kept in a constanttemperature oven set at 180° C. for 3 hours. A Hazen color number (APHA)of the 1,3-butylene glycol product after the 1,3-butylene glycol producthad been kept at 180° C. for 3 hours was measured using a colordifference meter (“ZE6000” available from Nippon Denshoku IndustriesCo., Ltd.) and a quartz cell with an optical path length of 10 mm. TheHazen color number (APHA) of the 1,3-butylene glycol product prior tothe test was similarly measured.

Color Aging Test 2

The target 1,3-butylene glycol product was placed in a wide-mouthbottle, and the bottle was stoppered tightly and kept in a constanttemperature oven set at 100° C. for 75 days. A Hazen color number (APHA)of the 1,3-butylene glycol product after the 1,3-butylene glycol producthad been kept at 100° C. for 75 days was measured using a colordifference meter (“ZE6000” available from Nippon Denshoku IndustriesCo., Ltd.) and a quartz cell with an optical path length of 10 mm.

Water Added Heating Test (Acid Concentration Analysis)

The target 1,3-butylene glycol product adjusted to a 90 wt. % aqueoussolution and then kept at 100° C. for 1 week was used as a sample for anacid concentration analysis performed according to the technique below.In addition, the 1,3-butylene glycol product prior to the test was alsosubjected to acid concentration analysis by the following technique.

Acid Concentration Analysis

The sample was measured using an automatic potentiometric titrator(AT-510 available from Kyoto Electronics Manufacturing Co., Ltd.).First, 50 g of the sample was diluted with 50 g of distilled water andtitrated with 0.01 N aqueous sodium hydroxide solution from a burettewith stirring until the titration was automatically stopped at theendpoint. Then, the acid concentration (acid content) in terms of aceticacid was calculated based on the following equation.

Acid concentration (wt. %)=titration volume (mL)×F×A×(100/sample amount(g))

F: 1.0 (factor of the 0.01 N aqueous sodium hydroxide solution)

A: 0.0006 (grams of acetic acid corresponding to 1 mL of the aqueoussodium hydroxide solution)

Odor Test

The target 1,3-butylene glycol product (100 mL) was placed in awide-mouth reagent bottle (internal volume: 100 mL), and the bottle wasstoppered tightly and allowed to stand at room temperature for a while(about 120 minutes). Then, the stopper was opened, the content wastransferred to a 300-mL wide-mouth beaker, and 100 mL of pure water wasadded into the beaker to make a total of 200 mL. The wide-mouth beakerwas shaken manually to stir the content, and the odor was thenimmediately smelled and scored according to the following evaluation.The same odor test was performed also on the sample after thecoloration-over-time test 1, and the sample after the water addedheating test.

1: Odor is not sensed

2: Slightly odorous

3: Odor is clearly sensed

Considerations of Results

The results of the comparative examples and the examples are shown inTable 1, Table 2, and Table 3.

TABLE 1 Comparative Comparative Comparative Comparative Example ExampleExample Example 1 Example 2 Example 3 Example 4 1 2 3 Charge into Part100 100 ← 100 100 ← ← dehydration 1,3 BG GC area % 56 66 ← 76 56 ← ←column A Water wt. % 40 30 ← 20 40 ← ← AD ppm 130 145 ← 155 130 ← ← CRppm 89 110 ← 117 89 ← ← Low boiling substance 3 3 ← 3 3 ← ← GC area %High boiling substance 1 1 ← 1 1 ← ← GC area % Reflux ratio of 0.5 0.5 ←1 1 50 50 dehydration columu A Distillate from Part 42 32 ← 23 43 43 43dehydration column A 1,3 BG % 99.3 99.8 ← 99.8 99.6 99.9 or 99.6recovery ratio greater Charge into Part 100 ← ← ← ← ← ← high boiling 1,3BG GC area % 96.6 97.4 ← 97.9 97.4 97.9 ← point Water wt.% 1.2 1.1 ← 0.70.9 0.2 ← component AD ppm 63 48 ← 39 20 9 9 removal CR ppm 45 37 ← 2319 12 9 column C Low boding substance 1.6 1.1 ← 0.8 0.8 0.3 ← GC area %High boiling substance 1.8 1.5 ← 1.3 1.8 1.8 ← GC area % High boilingReflux ratio 0.02 0.02 0.02 0.02 0.05 0.05 0.05 point Distillationextraction 80 80 80 80 80 80 80 component part removal Bottom extractionpart 2020 20 20 20 20 20 column C Recycle Absent Absent Absent AbsentAbsent Absent Absent 1,3 BG recovery 81 81 81 81 82 81 81 ratio % Chargeinto Part 100 100 ← 100 100 ← 100 product 1,3 BG GC area % 97.8 98.3 ←98.6 99.0 99.1 99.2 column F Water wt.% 1.3 1.2 ← 0.8 1 0.3 0.3 AD ppm45 39 ← 38 20 9 9 CR ppm 20 12 ← 139 6 6 Low boiling substance 1.0 0.6 ←0.6 0.4 0.3 0.3 GC area % High boiling substance 1.2 1.1 ← 0.8 0.6 0.60.5 GC area % Reflux ratio of 0.05 0.05 0.05 0.1 0.5 0.5 10 productcolumn F Distillation Part 20 20 30 20 10 10 1 column F from productRecycle Absent Absent Absent Absent Absent Absent Absent Bottom Part 8080 70 80 90 90 99 (product) from 1,3 BG GC area % 98.3 98.5 98.4 98.899.2 99.3 99.5 product Water wt. % 0.6 0.4 0.2 0.2 0.2 0.1 0.1 column FAD ppm 5 4 2 2 1.5 0.7 1 CR ppm 4 2 1.3 1.3 0.9 0.7 0.7 Low boilingsubstance 0.2 0.1 0.1 0.1 0.08 0.05 0.05 GC area % High boilingsubstance 1.5 1.4 1.5 1.1 0.7 0.7 0.5 GC area % Initial boiling point °C. 193.2 199.0 203.0 203.1 203.3 206.7 206.7 Dry point ° C. 210.3 210.1210.2 209.5 209 208.9 208.8 PMT min 0 5 30 30 35 45 40 1,3 BG recovery81 80 70 80 90 90 99 or ratio % greater Example Example Example ExampleExample Example Example 4 5 6 7 8 9 10 Charge into Part 100 ← ← ← ← ← ←dehydration 1,3 BG GC area % 66 ← ← ← ← ← ← column A Water wt. % 30 ← ←← ← ← ← AD ppm 145 ← ← ← ← ← ← CR ppm 110 ← ← ← ← ← ← Low boilingsubstance 3 ← ← ← ← ← ← GC area % High boiling substance 1 ← ← ← ← ← ←GC area % Reflux ratio of 2 10 20 20 20 50 100 dehydration columu ADistillate from Part 33 33 33 33 33 33 33 dehydration column A 1,3 BG %99.9 99.9 or 99.9 or 99.9 or 99.9 or 99.9 or 99.9 or recovery ratiogreater greater greater greater greater greater Charge into Part ← ← ← ←← ← ← high boiling 1,3 BG GC area % 98.2 98.3 98.3 98.3 98.3 98.3 98.4point Water wt. % 0.5 0.1 0.08 0.08 0.08 0.03 0.02 component AD ppm 3818 13 13 13 5 4 removal CR ppm 30 12 11 11 11 5 3 column C Low bodingsubstance 0.3 0.2 0.2 0.2 0.2 0.2 0.1 GC area % High boiling substance1.5 1.5 1.5 1.5 1.5 1.5 1.5 GC area % High boiling Reflux ratio 0.050.05 0.05 0.05 0.05 0.05 0.05 point Distillation extraction 80 80 80 8080 80 80 component part removal Bottom extraction part 20 20 20 20 20 2020 column C Recycle Absent Absent Absent Absent Absent Absent Absent 1,3BG recovery 81 81 81 81 81 81 81 ratio % Charge into Part 100 ← ← ← ← ←← product 1,3 BG GC area % 99.2 99.3 99.3 99.3 99.3 99.3 99.4 column FWater wt.% 0.6 0.3 0.2 0.2 0.2 0.1 0.08 AD ppm 29 16 10 11 9 3 2 CR ppm13 5 3 3 3 2 1 Low boiling substance 0.3 0.2 0.2 0.2 0.2 0.2 0.1 GC area% High boiling substance 0.5 0.5 0.5 0.5 0.5 0.5 0.5 GC area % Refluxratio of 0.5 0.5 2 100 500 2 2 product column F Distillation Part 10 101 1 1 1 1 column F from product Recycle Present Present Present PresentPresent Present Present Bottom Part 90 90 99 99 99 99 99 (product) from1,3 BG GC area % 99.4 99.4 99.4 99.5 99.5 99.4 99.5 product Water wt. %0.2 0.1 0.1 0.003 0.002 0.05 0.04 column F AD ppm 2 1.1 1 0.2 less than0.3 less than 0.2 0.2 CR ppm 1 0.7 0.6 0.1 less than 0.2 less than 0.10.1 Low boiling substance 0.04 0.03 0.07 0.004 0.003 0.06 0.03 GC area %High boiling substance 0.6 0.6 0.5 0.5 0.5 0.5 0.5 GC area % Initialboiling point ° C. 203.8 206.7 206.8 208.4 208.4 207.5 207.2 Dry point °C. 208.9 208 9 208.8 208.8 208.8 208.8 208.8 PMT min 30 40 40 55 60 5055 1,3 BG recovery 99 or 99 or 99 or 99 or 99 or 99 or 99 or ratio %greater greater greater greater greater greater greater

TABLE 2 Example Example Example Example Example Example Example ExampleExample 11 12 13 14 15 16 17 18 19 Charge into Part 100 ← ← 100 ← ← ← ←← dehydration 1,3 BG GC 76 ← ← 66 ← ← ← ← ← column A area % Water wt. %20 ← ← 30 ← ← ← ← ← AD ppm 155 ← ← 145 ← ← ← ← ← CR ppm 117 ← ← 110 ← ←← ← ← Low boiling 3 ← ← 3 ← ← ← ← ← substance GC area % High boiling 1 ←← ← ← 12 ← ← ← substance GC area % Reflux ratio of 2 10 100 10 10 10 toto 10 dehydration column A Distillate from Part 23 23 23 33 33 33 33 3323 dehydration column A 1,3 BG % 99.8 99.9 or 99.9 or 99.8 99.8 99.899.8 99.8 99.8 recovery ratio greater greater Charge into Part 100 ← ← ←← ← ← ← ← high boiling 1,3 BG GC 98.4 98.5 98.6 98.3 ← 98.1 98.3 ← ←point area % component Water wt. % 0.1 0.08 0.01 0.1 ← 0.1 0.1 ← ←removal AD ppm 29 15 2 18 ← 18 18 ← ← column C CR ppm 21 8 1 12 12 12 ←← Low boiling 0.3 0.2 0.1 0.2 ← 0.2 0.2 ← ← substance GC area % Highboiling 1.3 1.3 1.3 1.5 1.7 1.5 ← ← substance GC area % High boilingReflux ratio 0.05 0.05 0.05 0.1 0.5 0.5 0.5 1 2 point Distillation 80 8080 90 90 90 95 95 95 component extraction part removal Bottom 20 20 2010 10 10 5 5 5 column C extraction part Recycle Absent Absent AbsentAbsent Absent Present Absent Absent Absent 1,3 BG recovery 81 81 81 9191 99.9 or 96 96 96 ratio % greater Charge into Part 100 ← ← 100 100 100100 100 100 product 1,3 BG GC 99.3 99.4 99.5 99.4 99.6 99.5 99.5 99.799.7 column F area % Water wt. % 0.3 0.1 0.09 0.3 0.3 0.3 0.3 0.3 0.3 ADppm 22 12 1 10 9 10 10 9 8 CR ppm 14 5 0.7 5 6 6 5 5 5 Low boiling 0.30.2 0.1 0.2 0.2 0.2 0.2 0.2 0.2 substance GC area % High boiling 0.4 0.40.4 0.4 0.3 0.3 0.3 0.1 0.09 substance GC area % Reflux ratio of 1 2 2 11 1 1 1 1 product column F Distillate from Part 10 1 1 10 10 10 10 10 10product Recycle Present Present Present Present Present Present PresentPresent Present column F Bottom Part 90 99 99 90 90 90 90 90 90(product) from 1,3 BG GC 99.4 99.4 99.5 99.5 99.6 99.6 99.6 99.9 99.9product area % column F Water wt. % 0.06 0.05 0.04 0.05 0.05 0.05 0.050.05 0.05 AD ppm 1.6 1 less than 0.9 0.8 0.8 0.9 0.8 0.9 0.2 CR ppm 10.8 less than 0.7 0.6 0.6 0.5 0.5 0.4 0.1 Low boiling 0.09 0.07 0.050.02 0.02 0.02 0.02 0.02 0.02 substance GC area % High boiling 0.5 0.50.5 0.5 0.2 0.4 0.4 0.1 0.09 substance GC area % Initial boiling 207.3207.5 207.2 207.5 207.5 207.5 207.5 207.5 207.5 point ° C. Dry point °C. 208.9 208.9 208.9 208.8 208.6 208.8 208.8 208.6 208.5 PMT min 35 4060 45 45 45 45 45 45 1,3 BG recovery 90 99 or 99 or 99.9 or 99.9 or 99.9or 99.9 or 99.9 or 99.9 or ratio % greater greater greater greatergreater greater greater greater Example Example Example Example ExampleExample Example Example 20 21 22 23 24 25 26 27 Charge into Part ← ← 100100 100 100 100 100 dehydration 1,3 BG GC ← ← 56 76 9 66 67 69 column Aarea % Water wt. % ← ← 40 20 90 30 30 30 AD ppm ← ← 130 155 85 970 145 3CR ppm ← ← 89 117 71 390 110 1 Low boiling ← ← 3 3 0.4 3 3 1 substanceGC area % High boiling ← ← 1 1 0.1 1 1 0.5 substance GC area % Refluxratio of 10 10 0.5 100 20 2 0.3 10 dehydration column A Distillate fromPart 33 33 42 23 91 33 32 32 dehydration column A 1,3 BG % 99.8 99.899.3 99.9 or 99.0 99.9 or 99.8 99.9 or recovery ratio greater greatergreater Charge into Part ← ← 100   100 100 100 4 high boiling 1,3 BG GC← ← 96.6 98.6 97.5 98.2 96.7 99.1 point area % component Water wt. % ← ←1.2 0.01 3 0.5 1.3 0.1 removal AD ppm ← ← 63 2 9 22.1 61 0.3 column CCRppm ← ← 45 1 4 128 48 0.2 Low boiling ← ← 1.6 0.1 1.1 0.3 1.8 0.1substance GC area % High boiling ← ← 1.8 1.3 1.4 1.5 1.5 0.8 substanceGC area % High boiling Reflux ratio 5 20 0.1 1 1 0.05 0.05 1 pointDistillation 95 95 90 90 90 80 80 95 component extraction part removalBottom 5 5 10 10 10 20 20 5 column C extraction part Recycle AbsentAbsent Absent Absent Absent Absent Absent Absent 1,3 BG recovery 96 9692 91 91 81 81 96 ratio % Charge into Part too 100 100 — 100 100 100 tooproduct 1,3 BG GC 99.7 99.7 98.7 — 98.7 99.2 97.6 99.7 column F area %Water wt. % 0.3 0.3 1.2 — 3 0.7 1.4 0.3 AD ppm 8 9 43 — 7 205 54 0.3 CRppm 4 5 17 — 3 110 38 0.2 Low boiling 0.2 0.2 0.9 — 0.8 0.3 1.8 0.1substance GC area % High boiling 0.07 0.06 0.4 — 0.5 0.5 0.6 0.2substance GC area % Reflux ratio of 1 1 5 — 10 10 20 1 product column FDistillate from Part 10 10 10 — 10 10 10 10 product Recycle PresentPresent Present — Present Present Present Present column F Bottom Part90 90 96 — 90 96 90 90 (product) from 1,3 BG GC 99.9 99.9 99.4 99.5 99.499.4 99.3 99.8 product area % column F Water wt. % 0.05 0.05 0.1 0.090.1 6.62 0.01 6.65 AD ppm 0.9 0.8 1.1 1.5 0.3 1.2 0.5 less than 0.2 CRppm 0.4 0.3 0.4 1 0.2 1.1 0.4 less than 6.1 Low boiling 0.02 0.02 0.10.1 0.02 0.004 0.03 6.01 substance GC area % High boiling 0.08 0.07 0.50.4 0.6 0.6 0.7 0.2 substance GC area % Initial boiling 207.6 207.6206.8 206.9 206.7 208.0 207.8 207.6 point ° C. Dry point ° C. 208.5208.4 208.8 208.8 208.9 208.9 208.9 208.6 PMT min 45 45 45 35 50 35 4565 1,3 BG recovery 99.9 or 99.9 or 99.9 or — 99.9 or 99 or 99 or 99.9 orratio % greater greater greater greater greater greater greater

TABLE 3 Compar- Compar- ative ative Exam- Exam- Exam- Exam- Exam- ple 1ple 2 ple 1 ple 5 ple 7 1,3 BG GC area % 98.3 98.5 99.2 99.4 99 5 Waterwt. % 0.6 0.4 0.2 0.1 0.003 AD ppm 5 4 1.5 1.1 0.2 CR ppm 4 2 0.9 0.70.1 Low boiling substance GC area % 0.2 0.1 0.08 0.03 0.004 High boilingsubstance GC area % 15 1.4 0.7 0.6 0.5 Initial boiling point ° C. 193.2199 203.3 206.7 208.4 Dry point ° C. 210.3 210.1 209 208.9 208.9 PMT min0 5 35 40 55 Methyl vinyl ketone ppm 11 10 6 2 less than 0.2 Acetone ppm10 9 5 2 less than 0.2 Butylaldehyde ppm 9 8 5 2 less than 0.2 Acetaldolppm 10 10 6 2 less than 0.2 Compound ppm of Formula (1) 11 10 6 1.4 lessthan 0.2 Compound ppm of Formula (2) 9 8 5 1.1 0.5 Compound ppm ofFormula (3) 9 8 4 1 0.4 Compounds ppm of Formula (4) + 8 8 4 0.9 0.3Formula (5) APHA before coloration test 7 7 4 2 1 Odor before colorationtest 2 2 1 1 l Odor after coloration test 1 3 2 2 1 1 APHA of colorationtest 1 85 79 25 17 10 APHA of coloration test 2 51 43 12 7 3 Acidcontent (ppm) before water 11 11 6 4 2 added heating test Odor beforewater added heating test 2 2 1 1 1 Acid content (ppm) after water added27 23 9 5 2 heating test Odor after water added heating test 3 3 2 1 1Exam- Exam- Exam- Exam- Exam- ple 12 ple 18 ple 24 ple 26 ple 27 1,3 BGGC area % 99.4 99.9 99.3 99.3 99.8 Water wt. % 0.05 0.05 0.03 0.03 0.05AD ppm 1 0.8 0.5 0.5 less than 0.2 CR ppm 0.8 0.5 0.4 0.4 less than 0.1Low boiling substance GC area % 0.07 0.02 0.2 0.03 0.01 High boilingsubstance GC area % 0.5 0.1 0.6 0.7 0.2 Initial boiling point ° C. 207.5207.5 206.7 207.8 207 6 Dry point ° C. 208.9 208.6 208.9 208.9 208.6 PMTmin 40 45 50 45 65 Methyl vinyl ketone ppm 0.3 0.9 less than 0.2 3 lessthan 0.2 Acetone ppm 0.2 0.8 less than 0.2 2 less than 0.2 Butylaldehydeppm 0.3 07 less than 0.2 2 less than 0 2 Acetaldol ppm less than 0.2 0.5less dian 0.2 2 less than 0.2 Compound ppm of Formula (1) less than 0 20.8 less than 0.2 2 less than 0.2 Compound ppm of Formula (2) 0.4 lessthan 0.2 0.6 0.3 less than 0.2 Compound ppm of Formula (3) 0.5 less than0.2 0.7 0.5 less than 0 2 Compounds ppm of Formula (4) + 0.3 less than0.2 0.4 0.2 less than 0.2 Formula (5) APHA before coloration test 2 2 12 1 Odor before coloration test 1 1 1 1 1 Odor after coloration test 1 1] 1 1 1 APHA of coloration test 1 12 13 11 18 7 APHA of coloration test2 4 5 3 8 2 Acid content (ppm) before water 3 3 2 4 1 added heating testOdor before water added heating test 3 1 1 1 1 Acid content (ppm) afterwater added 3 3 2 4 1 heating test Odor after water added heating test 11 1 1 1

From Comparative Example 1, Comparative Example 2, Example 1, Example 5,and Example 7, it can be seen that, for acetaldehyde, crotonaldehyde,and other impurities detected by the gas chromatographic analysis(quantification limit: 10 ppm), and methyl vinyl ketone, acetone,butylaldehyde, acetaldol, the compound represented by Formula (1), thecompound represented by Formula (2), the compound represented by Formula(3), the compound represented by Formula (4), and the compoundrepresented by Formula (5) detected by the GC-MS analysis, the lowercontents resulted in better long-term storage stability in terms ofcoloration, acid concentration and odor.

The same applies to Examples 7, 12, and 18. From Examples 12 and 18, thereduction in contents of methyl vinyl ketone, acetone, butylaldehyde,acetaldol, and the compound represented by Formula (1) having a boilingpoint less than that of 1,3 BG and the reduction in contents of thecompound represented by Formula (2), the compound represented by Formula(3), the compound represented by Formula (4), and the compoundrepresented by Formula (5) have a boiling point higher than that of 1,3BG were both effective for long-term stability. However, total reductionin contents of these impurities as well as in contents of acetaldehyde,crotonaldehyde, and other impurities detected by the gas chromatographicanalysis (quantification limit: 10 ppm) is most effective for long-termstability of the quality of the 1.3 BG product, and the stability of theproduct quality is significantly better in Example 7. Note that therewas no clear correlation between the contents of the impurities detectedby the gas chromatographic analysis other than 1,3 BG (thequantification limit of around 10 ppm) and contents of impurities, whichwere less than 10 ppm, ranging from methyl vinyl ketone to the compoundrepresented by Formula (5) detected by the GC-MS analysis. This isthought to result from slight variation in concentration of eachcomponent depending on the reaction conditions and the individualdistillation conditions.

Example 24 was a case where the water content of the charged liquid intothe dehydration column was extremely high, but shows the same tendencyas described above. The relationship between the overall behavior of theimpurities and the APHA and acid concentration (acid content) showed thesame tendency as in Example 7.

In Example 26, it can be seen that, while the concentration of1,3-butylene glycol in the charged liquid into the product column wasreduced, the quality of the 1,3 BG product could be maintained bymaintaining a relatively high reflux ratio of the product column.

It can be seen, from Examples 18 and 27, that the quality of the 1,3 BGproduct was further improved by increasing the hydrogen additionpressure, totally reacting the unsaturated compounds such as aldehydeand olefin and acetals in the reaction system, and adjusting thedistillation conditions in each distillation column.

As a summary of the above, configurations and variations of the presentdisclosure are described below.

[1] A 1,3-butylene glycol product in which at least one of eightcontents: a content of methyl vinyl ketone, a content of acetone, acontent of butylaldehyde, a content of acetaldol, a content of acompound represented by Formula (1) below, a content of a compoundrepresented by Formula (2) below, a content of a compound represented byFormula (3) below, and a total content of a compound represented byFormula (4) below and a compound represented by Formula (5) below, isless than 8 ppm (or 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppmor less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm orless).

[2] The 1,3-butylene glycol product according to [1], wherein at leasttwo (or three, four, five, six, seven, or eight) contents of the eightcontents: the content of methyl vinyl ketone, the content of acetone,the content of butylaldehyde, the content of acetaldol, the content ofthe compound represented by Formula (1) below, the content of thecompound represented by Formula (2) below, the content of the compoundrepresented by Formula (3) below, and the total content of the compoundrepresented by Formula (4) below and the compound represented by Formula(5) below, are each less than 8 ppm (or 7 ppm or less, 6 ppm or less, 5ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less,or 0.5 ppm or less).

[3] The 1,3-butylene glycol product according to [1] or [2], wherein atleast four (four, five, six, seven, or eight) contents of the eightcontents: the content of methyl vinyl ketone, the content of acetone,the content of butylaldehyde, the content of acetaldol, the content ofthe compound represented by Formula (1) below, the content of thecompound represented by Formula (2) below, the content of the compoundrepresented by Formula (3) below, and the total content of the compoundrepresented by Formula (4) below and the compound represented by Formula(5) below, are each less than 8 ppm (or 7 ppm or less, 6 ppm or less, 5ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less,or 0.5 ppm or less).

[4] The 1,3-butylene glycol product according to any one of [1] to 131,wherein a sum of the content of methyl vinyl ketone, the content ofacetone, the content of butylaldehyde, the content of acetaldol, thecontent of the compound represented by Formula (1), the content of thecompound represented by Formula (2), the content of the compoundrepresented by Formula (3), and the content of the compound representedby Formula (4) and the content of the compound represented by Formula(5) is less than 71 ppm (or 60 ppm or less, 50 ppm or less, 40 ppm orless, 30 ppm or less, 20 ppm or less, 18 ppm or less, 16 ppm or less, 14ppm or less, 12 ppm or less, ppm or less, 8 ppm or less, 7 ppm or less,6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2 ppm orless, 1 ppm or less, or 0.5 ppm or less).

[5] The 1,3-butylene glycol product according to any one of [1] to [4],wherein a sum of the content of methyl vinyl ketone, the content ofacetone, the content of butylaldehyde, the content of acetaldol, and thecontent of the compound represented by Formula (1) is less than 47 ppm(or, 40 ppm or less, 30 ppm or less, 25 ppm or less, 20 ppm or less, 18ppm or less, 16 ppm or less, 14 ppm or less, 12 ppm or less, ppm orless, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppm or less, 4 ppmor less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm orless), and a sum of the content of the compound represented by Formula(2), the content of the compound represented by Formula (3), the contentof the compound represented by Formula (4), and the content of thecompound represented by Formula (5) is less than 24 ppm (or ppm or less,18 ppm or less, 16 ppm or less, 14 ppm or less, 13 ppm or less, 12 ppmor less, 11 μm or less, 10 ppm or less, 9 ppm or less, 8 ppm or less, 7ppm or less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less,2 ppm or less, 1 ppm or less, or 0.5 ppm or less).

[6] The 1,3-butylene glycol product according to any one of [1] to [5],wherein at least the content of acetaldol is less than 8 ppm (or 7 ppmor less, 6 ppm or less, 5 ppm or less, 4 ppm or less, 3 ppm or less, 2ppm or less, 1 ppm or less, or 0.5 ppm or less).

[7] The 1,3-butylene glycol product according to any one of [1] to [6],wherein at least the content of the compound represented by Formula (3)is less than 8 ppm (or 7 ppm or less, 6 ppm or less, 5 ppm or less, 4ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or 0.5 ppm orless).

[8] The 1,3-butylene glycol product according to any one of [1] to [7],wherein a total content of methyl vinyl ketone, acetone, andbutylaldehyde is 24 ppm or less (or 20 ppm or less, 18 ppm or less, 16ppm or less, 14 ppm or less, 12 ppm or less, 11 ppm or less, 10 ppm orless, 9 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppmor less, 4 ppm or less, 3 ppm or less, 2 ppm or less, 1 ppm or less, or0.5 ppm or less).

[9] The 1,3-butylene glycol product according to any one of [1] to [8],wherein a total content of the compound represented by Formula (1), thecompound represented by Formula (2), the compound represented by Formula(4), and the compound represented by Formula (5) is 24 ppm or less.

[10] The 1,3-butylene glycol product according to any one of [1] to [9],which has a content of acetaldehyde of less than 4 ppm (or less than 2ppm, 1.8 ppm or less, 1.7 ppm or less, 1.5 ppm or less, 1.4 ppm or less,1.3 ppm or less, 1.2 ppm or less, 1.1 ppm or less, 1.0 ppm or less, 0.9ppm or less, 0.8 ppm or less, 0.7 ppm or less, 0.6 ppm or less, 0.5 ppmor less, 0.3 ppm or less, or 0.2 ppm or less).

[11] The 1,3-butylene glycol product according to any one of [1] to[10], which has a content of crotonaldehyde of less than 2 ppm (or lessthan 1.2 ppm, 1.0 ppm or less, 0.9 ppm or less, 0.8 ppm or less, 0.7 ppmor less, 0.6 ppm or less, 0.5 ppm or less, 0.4 ppm or less, 0.3 ppm orless, 0.2 ppm or less, or 0.1 ppm or less).

[12] The 1,3-butylene glycol product according to any one of [1] to[11], which has an acid concentration of less than 11 ppm (or 10 ppm orless, 9 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppmor less, 4 ppm or less, or 3 ppm or less) in terms of acetic acid, andan acid concentration of less than 23 ppm (or 20 ppm or less, 19 ppm orless, 18 ppm or less, 17 ppm or less, 16 ppm or less, 15 ppm or less, 14ppm or less, 13 ppm or less, 12 ppm or less, 11 ppm or less, 10 ppm orless, 9 ppm or less, 8 ppm or less, 7 ppm or less, 6 ppm or less, 5 ppmor less, 4 ppm or less, 3 ppm or less, or 2 ppm or less) in terms ofacetic acid after a 90 wt. % aqueous solution has been kept at 100° C.for 1 week.

[13] The 1,3-butylene glycol product according to any one of [1] to[12], in which an APHA is 6 or less (or 5 or less, 4 or less, 3 or less,or 2 or less), and, after the 1,3-butylene glycol product has been keptat 180° C. for 3 hours in air atmosphere, an APHA is 78 or less (or 65or less, 60 or less, 55 or less, 50 or less, 45 or less, 40 or less, 35or less, 30 or less, 25 or less, 20 or less, 18 or less, 15 or less, 14or less, 13 or less, 12 or less, 11 or less, 10 or less, 9 or less, 8 orless, or 7 or less).

[14] The 1,3-butylene glycol product according to any one of [1] to[13], in which, after the 1,3-butylene glycol product has been kept at100° C. for 75 days in air atmosphere, an APHA is 42 or less (35 orless, 30 or less, 25 or less, 20 or less, 18 or less, 16 or less, 15 orless, 14 or less, 13 or less, 12 or less, 11 or less, 10 or less, 9 orless, 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, 3 or less,or 2 or less).

[15] The 1,3-butylene glycol product according to any one of [1] to[14], which has an initial boiling point of higher than 203° C. (or 204°C. or higher, 205° C. or higher, 206° C. or higher, 207° C. or higher,or 208° C. or higher), and/or a dry point of 209° C. or lower.

[16] The 1,3-butylene glycol product according to any one of [1] to[15], which has a potassium permanganate test value of 30 minutes orlonger (or longer than 30 minutes, 32 minutes or longer, 35 minutes orlonger, 40 minutes or longer, 50 minutes or longer, or 60 minutes orlonger).

[17] The 1,3-butylene glycol product according to any one of [1] to[16], which has an area ratio (GC area ratio) of a peak of 1,3-butyleneglycol of greater than 98.7% (or 98.8% or greater, 98.9% or greater, 99%or greater, 99.1% or greater, 99.2% or greater, 99.3% or greater, 99.4%or greater, 99.5% or greater, 99.6% or greater, 99.7% or greater, or99.8% or greater), in a gas chromatographic analysis (GC analysis)performed under conditions set forth below,

The conditions for the gas chromatographic analysis are as follows:

Analytical Column: a column with dimethylpolysiloxane as a stationaryphase, having a length of 30 m, an inner diameter of 0.25 mm, and a filmthickness of 1.0 μm

Heating conditions: heating from 80° C. to 120° C. at 5° C./min, thenheating again to 160° C. at 2° C./min and maintaining for 2 minutes, andfurther heating to 230° C. at 10° C./min and maintaining at 230° C. for18 minutes

Sample Introduction Temperature: 250° C.

Carrier Gas: helium

Column Gas Flow Rate: 1 mL/min

Detector and Detection Temperature: a flame ionization detector (FID),280° C.

[18] The 1,3-butylene glycol product according to any one of [1] to[17], wherein a total area ratio of peaks shorter in retention time thanthe peak of 1,3-butylene glycol is less than 0.3% (or 0.28% or less,0.25% or less, 0.23% or less, 0.2% or less, 0.17% or less, 0.15% orless, 0.12% or less, 0.1% or less, 0.07% or less, 0.04% or less, 0.03%or less, 0.02% or less, 0.01% or less, 0.007% or less, 0.005% or less,or 0.002% or less) in the gas chromatographic analysis (GC analysis)performed under conditions set forth above.

[19] The 1,3-butylene glycol product according to any one of [1] to[18], wherein a total area ratio of peaks longer in retention time thanthe peak of 1,3-butylene glycol is less than 1.2% (or 1% or less, 0.9%or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% orless, 0.3% or less, 0.2% or less, or 0.1% or less).

[20] The 1,3-butylene glycol product according to any one of [1] to[19], which has a content of water of less than 0.4 wt. % (or 0.3 wt. %or less, 0.2 wt. % or less, 0.1 wt. % or less, 0.07 wt. % or less, 0.05wt. % or less, 0.03 wt. % or less, 0.02 wt. % or less, 0.01 wt. % orless, or 0.005 wt. % or less).

[21] A moisturizer containing the 1,3-butylene glycol product describedin any one of [1] to [20].

[22] The moisturizer according to [21], which has a content of the1,3-butylene glycol product described in any one of [1] to [20] of 10wt. % or greater (or 30 wt. % or greater, 50 wt. % or greater, 80 wt. %or greater, or 90 wt. % or greater).

[23] A cosmetic product containing the moisturizer described in [21] or[22].

[24] The cosmetic product according to [23], which has a content of the1,3-butylene glycol product described in any one of [1] to [20] from0.01 to 40 wt. % (or from 0.1 to 30 wt. %, from 0.2 to 20 wt. %, from0.5 to 15 wt. %, or from 1 to 10 wt. %).

[25] The cosmetic product according to [23] or [24], which is a skincosmetic product, a hair cosmetic, a sunscreen cosmetic product or amake-up cosmetic product.

[26] A method for producing 1,3-butylene glycol to yield purified1,3-butylene glycol from a reaction crude liquid containing 1,3-butyleneglycol,

the method including: performing dehydration including removing water bydistillation, removing a high boiling point component including removinga high boiling point component by distillation, and performing productdistillation to yield purified 1,3-butylene glycol,

wherein, in a product column for use in the performing productdistillation, a 1,3-butylene glycol charged liquid is subjected todistillation, the 1,3-butylene glycol charged liquid having a content ofacetaldehyde of 500 ppm or less (or 205 ppm or less, 200 ppm or less,150 ppm or less, 120 ppm or less, 100 ppm or less, 90 ppm or less, 80ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm orless, ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, orless than 2 ppm), a content of crotonaldehyde of 200 ppm or less (or 150ppm or less, 130 ppm or less, 110 ppm or less, 100 ppm or less, 80 ppmor less, 70 ppm or less, 60 ppm or less, 50 ppm or less, 40 ppm or less,30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm orless, 2 ppm or less, or less than 1 ppm), a content of water of 0.7 wt.% or less (or 0.6 wt. % or less, 0.5 wt. % or less, 0.4 wt. % or less,0.3 wt. % or less, 0.2 wt. % or less, or 0.1 wt. % or less), and aconcentration of 1,3-butylene glycol of 97.6 area % or greater (or 97.8area % or greater, 98 area % or greater, 98.2 area % or greater, 98.4area % or greater, 98.6 area % or greater, 98.8 area % or greater, 99area % or greater, 99.1 area % or greater, 99.2 area % or greater, 99.3area % or greater, 99.4 area % or greater, 99.5 area % or greater, 99.6area % or greater, 99.7 area % or greater, 99.8 area % or greater, or99.9 area % or greater) according to a gas chromatographic analysisperformed under conditions set forth below; and the distillation isperformed under a condition that a reflux ratio is 0.3 or greater (or0.4 or greater, 0.5 or greater, 1 or greater, 2 or greater, 3 orgreater, 4 or greater, 5 or greater, 6 or greater, 7 or greater, 8 orgreater, 9 or greater, 10 or greater, 20 or greater, 50 or greater, 400or greater, or 500 or greater).

The conditions for the gas chromatographic analysis are as follows:

Analytical Column: a column with dimethylpolysiloxane as a stationaryphase, having a length of 30 m, an inner diameter of 0.25 mm, and a filmthickness of 1.0 μm

Heating conditions: heating from 80° C. to 120° C. at 5° C./min thenheating again to 160° C. at 2° C./min and maintaining for 2 minutes, andfurther heating to 230° C. at 10° C./min and maintaining at 230° C. for18 minutes

Sample Introduction Temperature: 250° C.

Carrier Gas: helium

Column Gas Flow Rate: 1 mL/min

Detector and Detection Temperature: a flame ionization detector (FID),280° C.

[27] The method for producing 1,3-butylene glycol according to [26],wherein the distillation rate in the product column is less than 30 wt.% (or 29 wt. % or less, 28 wt. % or less, 27 wt. % or less, 26 wt. % orless, 25 wt. % or less, 24 wt. % or less, 23 wt. % or less, 22 wt. % orless, 21 wt. % or less, 20 wt. % or less, 19 wt. % or less, 18 wt. % orless, 17 wt. % or less, 16 wt. % or less, 15 wt. % or less, 12 wt. % orless, 10 wt. % or less, 8 wt. % or less, 5 wt. % or less, 3 wt. % orless, 2 wt. % or less, 1 wt. % or less, 0.8 wt. % or less, 0.6 wt. % orless, or 0.4 wt. % or less).

[28] The method for producing 1,3-butylene glycol according to [26] or[27], wherein at least a portion of a distillate of the product columnis recycled to a step before the performing product distillation (forexample, dehydration, dealcoholization, low boiling point componentremoval, or a step before these steps).

[29] The method for producing 1,3-butylene glycol according to [28],wherein an amount of the distillate of the product column, which isrecycled to the step prior to the product distillation, is 0.01 wt. % orgreater (or 0.05 wt. % or greater, 0.1 wt. % or greater, 0.5 wt. % orgreater, 1 wt. % or greater, 1.5 wt. % or greater, 2 wt. % or greater, 3wt. % or greater, 4 wt. % or greater, 5 wt. % or greater, 7 wt. % orgreater, 10 wt. % or greater, or 20 wt. % or greater) and less than 30wt. % with respect to a charged amount into the product column.

[30] The method for producing 1,3-butylene glycol according to any oneof [26] to [29], wherein a recovery ratio of 1,3-butylene glycol in theproduct column is greater than 80% (or 85% or greater, 90% or greater,95% or greater, or 99% or greater).

[31] The method for producing 1,3-butylene glycol according to any oneof [26] to [30], wherein, in a high boiling point component removalcolumn for use in the removing a high boiling point component, a chargedliquid containing 1,3-butylene glycol is subjected to distillation, thecharged liquid having a content of acetaldehyde of 500 ppm or less (or205 ppm or less, 200 ppm or less, 100 ppm or less, 90 ppm or less, 80ppm or less, 70 ppm or less, 60 ppm or less, 50 ppm or less, ppm orless, 30 ppm or less, 20 ppm or less, 10 ppm or less, 5 ppm or less,less than 2 ppm, or less than 1 ppm), a content of crotonaldehyde of 200ppm or less (or 110 ppm or less, 100 ppm or less, 80 ppm or less, 70 ppmor less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less,20 ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm orless, or less than 1 ppm), a content of water of 3 wt. % or less (or 2wt. % or less, 1.2 wt. % or less, 1.1 wt. % or less, 1.0 wt. % or less,0.95 wt. % or less, 0.9 wt. % or less, 0.8 wt. % or less, 0 7.7 wt. % orless, 0.6 wt. % or less, 0.5 wt. % or less, 0.4 wt. % or less, 0.3 wt. %or less, 0.2 wt. % or less, or 0.1 wt. % or less), and a concentrationof 1,3-butylene glycol of 95 area % or greater (or 96 area % or greater,96.7 area % or greater, 97 area % or greater, 98 area % or greater, or99 area % or greater) according to the gas chromatographic analysisperformed under the conditions set forth above, and the distillation isperformed under a condition that a reflux ratio is 0.03 or greater (or0.05 or greater, 0.1 or greater, 0.2 or greater, 0.3 or greater, 0.4 orgreater, 0.5 or greater, 0.6 or greater, 0.7 or greater, 0.8 or greater,0.9 or greater, 1 or greater, 1.2 or greater, 1.5 or greater, 2 orgreater, 3 or greater, 4 or greater, 5 or greater, 10 or greater, or 20or greater).

[32] The method for producing 1,3-butylene glycol according to any oneof [26] to [31], wherein a bottom ratio in the high boiling pointcomponent removal column for use in the removing a high boiling pointcomponent is less than 30 wt. % (or 25 wt. % or less, 20 wt. % or less,15 wt. % or less, 10 wt. % or less, 7 wt. % or less, 5 wt. % or less, 4wt. % or less, 3 wt. % or less, 2 wt. % or less, or 1 wt. % or less).

[33] The method for producing 1,3-butylene glycol according to any oneof [26] to [32], wherein the bottom ratio in the high boiling pointcomponent removal column for use in the removing a high boiling pointcomponent is 0.01 wt. % or greater (or 0.1 wt. % or greater, 0.5 wt. %or greater, 1 wt. % or greater, 2 wt. % or greater, 3 wt. % or greater,4 wt. % or greater, 5 wt. % or greater, 6 wt. % or greater, 7 wt. % orgreater, 8 wt. % or greater, 9 wt. % or greater, 10 wt. % or greater, 15wt. % or greater, or 20 wt. % or greater).

[34] The method for producing 1,3-butylene glycol according to any oneof [26] to [33], wherein a recovery ratio of 1,3-butylene glycol in thehigh boiling point component removal column for use in the removing ahigh boiling point component is greater than 80% (or 85% or greater, 90%or greater, 95% or greater, or 99% or greater).

[35] The method for producing 1,3-butylene glycol according to any oneof [26] to [34], wherein at least a portion of a bottom of the highboiling point component removal column for use in the removing a highboiling point component is recycled to a step before the removing a highboiling point component.

[36] The method for producing 1,3-butylene glycol according to [35],wherein an amount of the bottom of the high boiling point componentremoval column, which is recycled to the step prior to the removing ahigh boiling point component, is less than 30 wt. % (or 25 wt. %, 20 wt.% or less, 15 wt. % or less, 10 wt. % or less, 7 wt. % or less, 5 wt %or less, 4 wt. % or less, 3 wt. % or less, 2 wt. % or less, or 1 wt. %or less) with respect to a charged amount into the high boiling pointcomponent removal column.

[37] The method for producing 1,3-butylene glycol according to 1351 or1361, wherein the amount of the bottom of the high boiling pointcomponent removal column, which is recycled to the step prior to theremoving a high boiling point component, is 0.01 wt % or greater (or 0.1wt % or greater, 2 wt. % or greater, 3 wt % or greater, 4 wt. % orgreater, 5 wt. % or greater, 7 wt. % or greater, 10 wt. % or greater, or20 wt. % or greater) with respect to the charged amount into the highboiling point component removal column.

[38] A method for producing 1,3-butylene glycol to yield purified1,3-butylene glycol from a reaction crude liquid containing 1,3-butyleneglycol,

the method including:

performing dehydration including removing water by distillation andremoving a high boiling point component including removing a highboiling point component by distillation,

wherein, in a high boiling point component removal column for use in theremoving a high boiling point component, a charged liquid containing1,3-butylene glycol is subjected to distillation, the charged liquidhaving a content of acetaldehyde of 500 ppm or less (or 205 ppm or less,200 ppm or less, 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppmor less, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less,20 ppm or less, 10 ppm or less, 5 ppm or less, less than 2 ppm, or lessthan 1 ppm), a content of crotonaldehyde of 200 ppm or less (or 110 ppmor less, 100 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm orless, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm or less, or less than 1ppm), a content of water of 3 wt. % or less (or 2 wt. % or less, 1.2 wt.% or less, 0.4 wt. % or less, 0.3 wt. % or less, 0.2 wt. % or less, 0.1wt. % or less, 0.05 wt. % or less, or 0.03 wt. % or less), and aconcentration of 1,3-butylene glycol of 96.7 area % or greater (or 97%or greater, 98% or greater, or 99% or greater) according to a gaschromatographic analysis performed under conditions set forth below, andthe distillation is performed under a condition that a reflux ratio is0.03 or greater (or 0.1 or greater, 0.2 or greater, 0.3 or greater, 0.4or greater, 0.5 or greater, 0.6 or greater, 0.7 or greater, 0.8 orgreater, 0.9 or greater, 1 or greater, 1.2 or greater, 1.5 or greater, 2or greater, 3 or greater, 4 or greater, 5 or greater, 10 or greater, or20 or greater).

The conditions for the gas chromatographic analysis are as follows:

Analytical Column: a column with dimethylpolysiloxane as a stationaryphase, having a length of 30 m, an inner diameter of 0.25 mm, and a filmthickness of 1.0 μm

Heating conditions: heating from 80° C. to 120° C. at 5° C./min, thenheating again to 160° C. at 2° C./min and maintaining for 2 minutes, andfurther heating to 230° C. at 10° C./min and maintaining at 230° C. for18 minutes

Sample Introduction Temperature: 250° C.

Carrier Gas: helium

Column Gas Flow Rate: 1 mL/min

Detector and Detection Temperature: a flame ionization detector (FID),280° C.

[39] The method for producing 1,3-butylene glycol according to any oneof [26] to [38], wherein, in a dehydration column for use in theperforming dehydration, a charged liquid containing 1,3-butylene glycolis subjected to distillation, the charged liquid having a content ofacetaldehyde of 1000 ppm or less (or 900 ppm or less, 800 ppm or less,700 ppm or less, 600 ppm or less, 500 ppm or less, 400 ppm or less, 300ppm or less, 200 ppm or less, 155 ppm or less, 140 ppm or less, 100 ppmor less, 90 ppm or less, 80 ppm or less, 70 ppm or less, 60 ppm or less,50 ppm or less, 40 ppm or less, 30 ppm or less, 20 ppm or less, 10 ppmor less, 5 ppm or less, 3 ppm or less, 2 ppm or less, or 1 ppm or less),a content of crotonaldehyde of 400 ppm or less (or 300 ppm or less, 200ppm or less, 100 ppm or less, 150 ppm or less, 130 ppm or less, 117 ppmor less, 100 ppm or less, 90 ppm or less, 80 ppm or less, 70 ppm orless, 60 ppm or less, 50 ppm or less, 40 ppm or less, 30 ppm or less, 20ppm or less, 10 ppm or less, 5 ppm or less, 3 ppm or less, 2 ppm orless, or 1 ppm or less), a content of water of 90 wt. % or less (or 85wt. % or less, 80 wt. % or less, 70 wt. % or less, 60% wt. % or less, 50wt. % or less, 40 wt. % or less, 35 wt. % or less, 30 wt. % or less, 25wt. % or less, 15 wt. % or less, or 10 wt. % or less), and aconcentration of 1,3-butylene glycol of 95 area % or greater (or 96 area% or greater, 96.7 area % or greater, 97 area % or greater, 98 area % orgreater, or 99 area % or greater) according to the gas chromatographicanalysis performed under the conditions set forth above, and thedistillation is performed under a condition that a reflux ratio isgreater than 0.3 (or 0.4 or greater, 0.5 or greater, 0.6 or greater, 0.7or greater, 0.8 or greater, 0.9 or greater, 1 or greater, 1.1 orgreater, 1.2 or greater, 1.3 or greater, 1.4 or greater, 1.5 or greater,1.6 or greater, 1.7 or greater, 1.8 or greater, 1.9 or greater, 2 orgreater, 3 or greater, 4 or greater, 5 or greater, 6 or greater, 7 orgreater, 8 or greater, 9 or greater, 10 or greater, 15 or greater, 20 orgreater, 25 or greater, 30 or greater, or 40 or greater).

[40] The method for producing 1,3-butylene glycol according to any oneof [26] to [39], wherein a distillation ratio in the dehydration columnfor use in the performing dehydration is 95 wt. % or less (or 90 wt. %or less, 85 wt. % or less, 80 wt. % or less, 75 wt. % or less, 70 wt. %or less, 65 wt. % or less, 60 wt. % or less, 55 wt. % or less, 50 wt. %or less, 45 wt. % or less, 40 wt. % or less, 35 wt. % or less, 30 wt. %or less, 25 wt. % or less, 20 wt. % or less, 15 wt. % or less, 10 wt. %or less, or 5 wt. % or less).

[41] The method for producing 1,3-butylene glycol according to any oneof [26] to [40], wherein a recovery ratio of 1,3-butylene glycol in thedehydration column for use in the dehydration is 99.3% or greater.

[42] The method for producing 1,3-butylene glycol according to any oneof [26] to [41], wherein the reaction crude liquid containing1,3-butylene glycol is a reaction crude liquid produced by hydrogenreduction of an acetaldol.

[43] The method for producing 1,3-butylene glycol according to any oneof [26] to [42], further including at least one step selected fromalkali treatment including treating a process stream containing1,3-butylene glycol with a base, desalting including removing a salt ina process stream containing 1,3-butylene glycol, and dealcoholizationincluding removing a low boiling point substance containing an alcoholin a process stream containing 1,3-butylene glycol.

INDUSTRIAL APPLICABILITY

The 1,3-butylene glycol product according to the present disclosure hashigh purity and is colorless and odorless (or almost colorless andodorless), unlikely to cause coloration and odor over time, and/orunlikely to cause an acid concentration increase over time also in astate containing water. This 1,3-butylene glycol product can be used asa raw material for a moisturizer and a cosmetic product that haveexcellent moisturizing performance and can retain high quality for along period of time.

REFERENCE SIGNS LIST

-   A: Dehydration column-   B: Desalting column-   C: Distillation column for removing a high boiling point component    (high boiling point component removal column)-   D: Alkaline reactor-   E: Dealkalization column-   F: Product distillation column (product column)-   A-1, B-1. C-1, E-1, and F-1: Condenser-   A-2, C-2, and F-2: Reboiler-   X-1: Crude 1,3-butylene glycol-   X-2: Water (discharged water)-   X-3: A salt, a high boiling point component, and a portion of    1,3-butylene glycol-   X-4: A high boiling point component and a portion of 1,3-butylene    glycol-   X-5: Sodium hydroxide, a high boiling point component, and a portion    of 1,3-butylene glycol-   X-6: A low boiling point component and a portion of 1,3-butylene    glycol-   Y: 1,3-butylene glycol product

1. A 1,3-butylene glycol product in which at least one of eightcontents: a content of methyl vinyl ketone, a content of acetone, acontent of butylaldehyde, a content of acetaldol, a content of acompound represented by Formula (1) below, a content of a compoundrepresented by Formula (2) below, a content of a compound represented byFormula (3) below, and a total content of a compound represented byFormula (4) below and a compound represented by Formula (5) below, isless than 8 ppm


2. The 1,3-butylene glycol product according to claim 1, wherein a sumof the content of methyl vinyl ketone, the content of acetone, thecontent of butylaldehyde, the content of ace aldol, the content of thecompound represented by Formula (1), the content of the compoundrepresented by Formula (2), the content of the compound represented byFormula (3), the content of the compound represented by Formula (4), andthe compound represented by Formula (5), is less than 71 ppm.
 3. The1,3-butylene glycol product according to claim 1, wherein at least thecontent of acetaldol is less than 8 ppm.
 4. The 1,3-butylene glycolproduct according to claim 1, wherein at least the content of thecompound represented by Formula (3) is less than 8 ppm.
 5. The1,3-butylene glycol product according to claim 1, wherein a totalcontent of methyl vinyl ketone, acetone, and butylaldehyde is 24 ppm orless.
 6. The 1,3-butylene glycol product according to claim 1, wherein atotal content of the compound represented by Formula (1), the compoundrepresented by Formula (2), the compound represented by Formula (4), andthe compound represented by Formula (5) is 24 ppm or less.
 7. The1,3-butylene glycol product according to claim 1, which has a content ofacetaldehyde of less than 4 ppm and a content of crotonaldehyde of lessthan 2 ppm.
 8. The 1,3-butylene glycol product according too claim 1,wherein an acid concentration is less than 11 ppm in terms of aceticacid, and, after a 90 wt. % aqueous solution of the 1,3-butylene glycolproduct has been kept at 100° C. for 1 week, the aqueous solution has anacid concentration of less than 23 ppm in terms of acetic acid.
 9. The1,3-butylene glycol product according to claim 1, wherein an APHA is 6or less, and, after the 1,3-butylene glycol product has been kept at180° C. for 3 hours in air atmosphere, an APHA of 78 or less.
 10. The1,3-butylene glycol product according to claim 1, wherein an initialboiling point is higher than 203° C. and/or a dry point is 209° C. orlower.
 11. The 1,3-butylene glycol product according to claim 1, whereina potassium permanganate test value is 30 minutes or longer.
 12. Amoisturizer comprising the 1,3-butylene glycol product described inclaim
 1. 13. A cosmetic product comprising the moisturizer described inclaim
 12. 14. A method for producing 1,3-butylene glycol to yieldpurified 1,3-butylene glycol from a reaction crude liquid including1,3-butylene glycol, the method comprising: performing dehydrationincluding removing water by distillation, removing a high boiling pointcomponent including removing a high boiling point component bydistillation, and performing product distillation to yield purified1,3-butylene glycol, wherein, in a product column for use in theperforming product distillation, a 1,3-butylene glycol charged liquid issubjected to distillation under a condition that a reflux ratio is 0.3or greater, the 1,3-butylene glycol charged liquid having a content ofacetaldehyde of 500 ppm or less, a content of crotonaldehyde of 200 ppmor less, a content of water of 0.7 wt. % or less, and a concentration of1,3-butylene glycol of 97.6 area % or greater, according to a gaschromatographic analysis performed under conditions, and the conditionsfor the gas chromatographic analysis are as follows: Analytical Column:a column with dimethylpolysiloxane as a stationary phase, having alength of 30 m, an inner diameter of 0.25 mm, and a film thickness of1.0 μm Heating conditions: heating from 80° C. to 120° C. at 5° C./min,then heating again to 160° C. at 2° C./min and maintaining for 2minutes, and further heating to 230° C. at 10° C./min and maintaining at230° C. for 18 minutes Sample Introduction Temperature: 250° C. CarrierGas: helium Column Gas Flow Rate: 1 mL/min Detector and DetectionTemperature: a flame ionization detector (FID), 280° C.
 15. The methodfor producing 1,3-butylene glycol according to claim 14, wherein atleast a portion of a distillate of the product column is recycled to astep before the performing the product distillation, the step includingdehydration, dealcoholization, low boiling point component removal, or astep before the dehydration, the dealcoholization, the low boiling pointcomponent removal.
 16. A method for producing 1,3-butylene glycol toyield purified 1,3-butylene glycol from a reaction crude liquidincluding 1,3-butylene glycol, the method comprising: performingdehydration including removing water by distillation and removing a highboiling point component including removing a high boiling pointcomponent by distillation, wherein, in a high boiling point componentremoval column for use in the removing a high boiling point component, a1,3-butylene glycol-containing charged liquid is subjected todistillation under a condition that a reflux ratio is 0.03 or greater,the 1,3-butylene glycol-containing charged liquid having a content ofacetaldehyde of 500 ppm or less, a content of crotonaldehyde of 200 ppmor less, a content of water of 3 wt. % or less, and a concentration of1,3-butylene glycol of 96.7 area % or greater, according to a gaschromatographic analysis performed under conditions, and the conditionsfor the gas chromatographic analysis are as follows: Analytical Column:a column with dimethylpolysiloxane as a stationary phase, having alength of 30 m, an inner diameter of 0.25 mm, and a film thickness of1.0 μm Heating conditions: heating from 80° C. to 120° C. at 5° C./min,then heating again to 160° C. at 2° C./min and maintaining for 2minutes, and further heating to 230° C. at 10° C./min and maintaining at230° C. for 18 minutes Sample Introduction Temperature: 250° C. CarrierGas: helium Column Gas Flow Rate: 1 mL/min Detector and DetectionTemperature: a flame ionization detector (FID), 280° C.
 17. The methodfor producing 1,3-butylene glycol according to claim 14, wherein thereaction crude liquid including 1,3-butylene glycol is a reaction crudeliquid produced by hydrogen reduction of an acetaldol.
 18. The methodfor producing 1,3-butylene glycol according to claim 14, furthercomprising at least one step selected from alkali treatment includingtreating a process stream including 1,3-butylene glycol with a base,desalting including removing a salt in a process stream including1,3-butylene glycol, and dealcoholization including removing a lowboiling point substance in a process stream including 1,3-butyleneglycol, the low boiling point substance including an alcohol.
 19. Themethod for producing 1,3-butylene glycol according to claim 16, whereinthe reaction crude liquid including 1,3-butylene glycol is a reactioncrude liquid produced by hydrogen reduction of an acetaldol.
 20. Themethod for producing 1,3-butylene glycol according to claim 16, furthercomprising at least one step selected from alkali treatment includingtreating a process stream including 1,3-butylene glycol with a base,desalting including removing a salt in a process stream including1,3-butylene glycol, and dealcoholization including removing a lowboiling point substance in a process stream including 1,3-butyleneglycol, the low boiling point substance including an alcohol.